Highlights
-
Two-dimensional transition metal carbides/nitrides (MXenes) as co-catalysts were summarized and classified according to the different synthesis methods used: mechanical mixing, self-assembly, in situ decoration, and oxidation.
-
The working mechanism for MXenes application in photocatalysis was discussed. The improved photocatalytic performance was attributed to enhancement of charge separation and suppression of charge recombination.
Abstract
Since their seminal discovery in 2011, two-dimensional (2D) transition metal carbides/nitrides known as MXenes, that constitute a large family of 2D materials, have been targeted toward various applications due to their outstanding electronic properties. MXenes functioning as co-catalyst in combination with certain photocatalysts have been applied in photocatalytic systems to enhance photogenerated charge separation, suppress rapid charge recombination, and convert solar energy into chemical energy or use it in the degradation of organic compounds. The photocatalytic performance greatly depends on the composition and morphology of the photocatalyst, which, in turn, are determined by the method of preparation used. Here, we review the four different synthesis methods (mechanical mixing, self-assembly, in situ decoration, and oxidation) reported for MXenes in view of their application as co-catalyst in photocatalysis. In addition, the working mechanism for MXenes application in photocatalysis is discussed and an outlook for future research is also provided.
Similar content being viewed by others
Avoid common mistakes on your manuscript.
1 Introduction
Energy shortage and environmental pollution have become the two major issues faced by humanity due to limited fossil fuel resources and increasing consumption. Developing sustainable and clean energy is the key to addressing these two problems [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]. In being clean and inexhaustible, solar energy shows great potential to be one of the most promising future energy sources. Solar energy can be exploited in photovoltaic technologies [16], CO2 photoreduction [17, 18], N2 photo-fixation [19], degradation of organic compounds [20,21,22,23,24,25,26], and photocatalytic water splitting [27]. In renewable hydrogen fuel-based photocatalytic water-splitting systems [28,29,30], photocatalysts play a critical role [31, 32]. Photo-catalyzed solar energy conversion can be divided into three steps: (1) light absorption, (2) charge separation and transfer, and (3) surface reaction. Any improvement on each of these steps will contribute to enhancing the total conversion efficiency. Conventional photocatalysts such as TiO2, g-C3N4, and CdS demonstrate low photocatalytic efficiency due to rapid charge recombination in these materials. Using noble metals such as Pt, Ru, and Pd as co-catalysts will increase cost, although such materials can enhance charge separation ability and suppress recombination of charges. A co-catalyst that is both efficient and cheap is thus urgently needed to promote the development of photocatalysis.
MXenes, comprising transition metal carbides, nitrides, and carbonitrides, are a new family of two-dimensional (2D) materials that have attracted much attention in recent years [2]. The general formula of MXene is Mn+1Xn (n = 1, 2, 3), where M represents a transition metal, such as Sc, Ti, Zr, Hf, V, Nb, Ta, and Mo, while X represents C and/or N. Owing to their unique structure and superior photoelectronic properties, layered structure MXenes show various potential applications in different areas, such as energy storage [3, 33,34,35,36,37,38], electromagnetic interference shielding [39, 40], gas sensors [41], wireless communication [42], water treatment [43, 44], solar cells [45,46,47], and catalysis [41, 48,49,50,51]. 2D MXenes are being increasingly studied in the past few years, as evidenced by the rapidly increasing number of scientific articles published per year (Fig. 1a). MXenes are usually synthesized by selectively etching the A layer from MAX phases, which constitute a family of tertiary ductile ceramics, where the A layer is made of an element such as Al, Ga [52], or Si [53]. After selective etching of the A layer, 2D MX layers with surface functional groups (–O, –OH, –F, or a mixture of several groups denoted as Tx) are left. The most widely used methods for selective etching are wet chemical HF etching and in situ HF etching (using a mixture of acids and fluoride salts), although other routes using tetramethylammonium hydroxide (TMAOH) [54, 55], electrochemical [56, 57], or etching with NaOH [58], and ZnCl2 [49]) have also been explored. Generally, multilayered MXenes are produced by HF etching, whereas single or few-layered MXene flakes are obtained by in situ HF etching or through delamination of a multilayered MXene by intercalation of large organic molecules (Fig. 1b). The etching methods of Ti3C2Tx MXene, which is the first discovered and the most studied MXene, have been reviewed elsewhere [59, 60].
In view of the rapid development in the application of 2D MXenes, several reviews on their synthesis [59,60,61], and application in energy storage [33, 48, 62] and catalysis [51] have been reported. MXenes are promising for application in photocatalysis [63] because of their large surface area, good conductivity, presence of a sufficient number of active sites, and containing suitable elements for effective photocatalysis, but they cannot be directly used as photocatalysts since MXenes are generally not semiconductors [51, 62]. Although there are some MXene semiconductors that have been predicted theoretically [64,65,66,67,68], these have not yet been experimentally synthesized. In this review, we give a detailed discussion on MXene as a co-catalyst in photocatalysis and describe the different methods used for the synthesis of MXene-derived photocatalysts, along with problems encountered in this system and a prospective outlook on future research in this field.
2 Synthetic Methods for MXenes as Co-catalysts in Photocatalysis
In view of their good conductivity and large surface area, MXenes have been applied in photocatalysis both to replace noble metal co-catalysts and to enhance the charge separation ability of the photocatalyst (Fig. 2). The most common methods used for the preparation of photocatalyst composites include mechanical mixing, self-assembly, in situ decoration and oxidation, or a combination of the three methods.
2.1 Mechanical Mixing and Self-assembly
Mechanical mixing is the easiest method to form photocatalyst composites. Stirring the two components in the liquid phase or grinding of powders can be used for sample preparation. Interestingly, due to electrostatic attraction, photocatalysts with positive charge are easily combined with MXenes whose surfaces are enriched with negative charges, leading to self-assembled photocatalyst composites. In addition, the self-assembling property could be further improved by using other induced techniques simultaneously, where the photocatalysts and co-catalysts are prepared in advance [44].
An et al. [72] demonstrated that synergetic effects of Ti3C2 MXene and Pt when used as dual co-catalysts enhanced the photoactivity of g-C3N4 for hydrogen evolution (Fig. 3a), where HF-etched exfoliated Ti3C2 and g-C3N4 were mixed in liquid by stirring followed by photodeposition of Pt on the composites. The photoactivity of the dual co-catalysts-modified photocatalysts (g-C3N4/Ti3C2/Pt) was much better than that of Pt- or Ti3C2-only systems, reaching 5.1 mmol h−1 g−1 in hydrogen production (Fig. 4a). This enhanced performance was due to the presence of Ti3C2 MXene that facilitated interfacial charge separation and carrier transport from the conduction band (CB) of g-C3N4 to Pt. Our group prepared g-C3N4/Ti3C2Tx composites by grinding g-C3N4 and Ti3C2Tx powders together followed by annealing in different gas atmospheres, to tune the surface termination groups (Fig. 4b) [74]. X-ray photoelectron spectroscopy data showed an increase in –O termination groups accompanied by a decrease in –F termination groups on the surface of Ti3C2. Ti3C2 with –O termination groups had better photoactivity, revealing that the presence of such groups in Ti3C2 had a positive effect on hydrogen production by increasing the number of active sites. Moreover, this finding was consistent with density functional theory (DFT) simulation results. The |ΔGH| of Ti3C2 with –O terminations was found to be as low as 0.01 eV, which is lower than that of Pt (111). In a similar study, Ye et al. [69] treated HF-etched Ti3C2 with KOH to convert –F groups into –OH groups, and then combined the KOH-treated Ti3C2 with TiO2 (P25) powder by stirring in water (Fig. 3c). DFT calculations demonstrated that –OH groups played the role of active sites for the adsorption and activation of CO2 reduction [69]. Experimentally, the photoactivities for CO2 reduction were increased 3 times and 277 times after KOH treatment, for CO and CH4, respectively (Fig. 4d). Interestingly, increasing the number of –OH groups not only improved the photo-conversion efficiency but also changed the nature of the products. The –OH groups resulting from KOH treatment provided more active sites for CO2 adsorption and enabled greater electron transfer to CO2 and facilitated its reduction to CH4. Though the surface termination groups can be changed through annealing and KOH treatments, –F groups could not be completely exchanged. More studies to precisely tailor the termination groups need to be carried out in the future.
Xie et al. [73] used an electrostatic self-assembly process to combine positively charged CdS nanosheets and Ti3C2 nanosheets (possessing negative charge) (Fig. 3b) for CO2 reduction (Fig. 4c). Cai et al. [75] synthesized Ag3PO4/Ti3C2 by electrostatically driven self-assembly method, which had the advantage of being a mild method that prevented Ti3C2 from oxidation. The composites showed better performance than reduced graphene oxide (rGO), and this preparation procedure provided a new direction to the preparation of semiconductor-MXene composites. Liu et al. [44] fabricated a 2D layered and stacked g-C3N4/Ti3C2 composite by evaporation-induced self-assembly and used it to degrade organic pollutants (ciprofloxacin) (Fig. 3d). Both photogenerated holes and superoxide radicals (·O2−) resulting from photogenerated electrons played important roles in ciprofloxacin decomposition (Fig. 4f); in this process, self-assembly was an efficient method that allowed intimate mixing of the components in the composite. The sample was also more homogeneous than mechanically mixed ones because of the electrostatic attraction between the charged entities. However, opposite charges on each surface were required for self-assembly, which limited wider application of this process. Therefore, other techniques to induce self-assembly such as evaporation-induced self-assembly were developed to widen the range of application of products [44].
The above-mentioned MXene-based composites prepared by mechanical mixing and self-assembly methods for photocatalysis application are summarized in Table 1. Results from all these works prove that 2D MXene is an efficient additive material to enhance charge separation and charge transfer during photocatalysis. In these two methods, the properties of MXenes are retained by avoiding high temperature and use of other solvents or surfactant. No change in oxidation or surface termination groups occurs in these synthesis methods. Therefore, these two are the easiest and allow synthesis under the mildest conditions.
2.2 In Situ Decoration of Semiconductors onto the Surface of MXenes
In contrast to composites prepared by mechanical mixing of materials, in situ decoration methods consist in synthesizing a different material directly onto the MXene surface. As a result, in situ synthetized materials and MXenes are chemically bonded, which could be an important advantage in some designs. However, the range of viable synthetic conditions for in situ decoration is limited, because MXenes are easily oxidized in solution, especially at high temperatures [107]. It is therefore necessary to use mild conditions to protect MXenes from oxidation, especially when mono- and few-layered MXenes are used. So far, g-C3N4, TiO2, CdS, and bismuth compounds have been bonded to various MXenes using this strategy.
g-C3N4 is one 2D semiconductor material that is combined with MXenes used as a co-catalyst in the photocatalysis process (Fig. 5). MXene can be added during the calcination of a precursor, such as melamine and thiourea, but the high calcination temperature (around 550 °C) may cause the oxidation of MXene into TiO2. The high photoactivity of g-C3N4/MXene is attributed to the efficient charge separation; moreover, the heterojunction formed by TiO2/g-C3N4 also plays an important role in charge separation [108]. Shao et al. [81] synthesized Ti2C/g-C3N4 by melamine calcination and used it in hydrogen production (Fig. 5a, d). Though the ratio of Ti2C in the composite was as low as 0.4 wt%, a peak due to TiO2 resulting from the oxidation of Ti2C could be seen in the XRD pattern. Liu et al. [19] synthesized TiO2@C/g-C3N4 heterojunction by melamine calcination (Fig. 5b), where Ti3C2 was oxidized to TiO2@C during the calcination process. This composite was highly effective in the reaction of nitrogen reduction to ammonia, with the best performance reaching as high as 250.6 μmol h−1 g−1, which was better than that of TiO2@C and g-C3N4 (Fig. 5e). Xu et al. [82] synthesized Ti3+-rich Ti3C2/g-C3N4 by calcination of thiourea and employed it as an electrode for CO2 reduction in a photoelectrocatalytic (PEC) system (Fig. 5c, f), achieving a total CO2 reduction rate of 25.1 mmol h−1 g−1. The Ti3+ species suppressed charge recombination at the Ti3C2/g-C3N4 heterojunctions, leading to a corresponding increase in CO2 conversion efficiency.
Apart from the above-mentioned synthesis methods, composite photocatalysts can also be synthesized by combining TiO2, a metal sulfide, or a bismuthide with MXene under hydrothermal conditions (Fig. 6). Gao et al. [83] synthesized TiO2/Ti3C2 nanocomposites by a hydrothermal method using TiSO4 as a precursor for methyl orange (MO) degradation (Fig. 6a), where small TiO2 particles could be observed on the surface of multilayered Ti3C2. Wang et al. [84] employed TiCl4 as the precursor in the hydrothermal synthesis of rutile TiO2/Ti3C2Tx for hydrogen production by water splitting (Fig. 6d). The photocatalytic activity of TiO2 when combined with other MXenes (Ti2CTx and Nb2CTx flakes) as co-catalysts was also explored; results proved that in general, MXenes could be used as effective co-catalysts for solar hydrogen production. Ran et al. [70] combined CdS and Ti3C2 particles by a one-step hydrothermal reaction (Fig. 6b). A hydrogen production rate of 14,342 μmol h−1 g−1 was achieved when using Ti3C2 as the co-catalyst; this performance is 136.6 times higher than that of the pure CdS photocatalyst. The effectivity and versatility of Ti3C2 MXene as a co-catalyst for photocatalytic hydrogen production was demonstrated by other metal sulfides (ZnS) [91] photocatalysts as well. Xie et al. [73] showed that Ti3C2 flakes enabled the local confinement of Cd2+ released during photo-corrosion and thus enhanced the stability of the metal sulfide. Besides CdS, In2S3/Ti3C2Tx hybrids synthesized by hydrothermal method have been used for methyl orange degradation as reported by Wang et al. [90]. Among the hybrids based on other additives (carbon nanotubes (CNT), rGO, MoS2, and TiO2), Ti3C2-based composites showed the best photocatalytic activity, which is attributed to their high electrical conductivity. Shi et al. [85] synthesized TiO2/C/BiVO4 composites by hydrothermal method for the degradation of Rhodamine B, where Ti3C2 was employed both as a support for the growth of BiVO4 nanoparticles and as a precursor for the generation of 2D-carbon upon oxidation. The electron transfer process was accelerated by the presence of Ti3C2-derived 2D-carbon layers, thus improving the photocatalytic performance for Rhodamine B degradation. Ultrathin 2D/2D heterojunction of MXene/Bi2WO6 prepared by the in situ growth of ultrathin Bi2WO6 nanosheets on the surface of ultrathin Ti3C2 nanosheets for photocatalytic CO2 reduction was reported by Cao et al. [88] (Fig. 6c). The CH4 and CH3OH yield were 4.6 times higher than those obtained with pristine Bi2WO6, which was ascribed to the enhanced CO2 adsorption arising from the increased specific surface area and improved pore structure of the layered heterojunction. The different composites/hybrids containing MXene or MXene-derived products prepared by hydrothermal methods and used in photocatalysis are listed in Table 1.
The synthetic process for MXenes-based composites includes doping into the photocatalysts or using MXene as a support for in situ decoration of the semiconductor photocatalyst. The chemical reactions taking place during photocatalyst formation led to increased interfacial area, thus providing greater possibilities for the transfer of photogenerated electrons. However, one disadvantage of this method is the oxidation of MXenes during photocatalyst synthesis. Although difficult to precisely characterize, conditions of formation of the photocatalysts may be too harsh and cause structural degradation of MXenes, especially in the case of single-layered MXenes, due to their lower stability toward oxidation.
2.3 MXene-Derived Photocatalysts
Different from mechanical mixing, self-assembly, and decoration methods, the in situ oxidation method using MXene (Ti3C2 is the most studied example) as a precursor for the synthesis of photocatalysts has also been explored (Fig. 7). Peng’s group tuned the facet of TiO2/Ti3C2 using a hydrothermal method without using an additional TiO2 precursor (Fig. 7a, b) [71, 93]. NaBF4 and NH4F were used as reagents to, respectively, control morphology in the synthesis of (001) TiO2/Ti3C2 and (111) TiO2/Ti3C2, which were then applied in methyl orange degradation. Both the facet type of TiO2 and the ratio of TiO2 to Ti3C2 could be controlled by changing the duration of the hydrothermal reaction. Jia et al. [94] obtained closely aggregated TiO2 nanorods with high carbon doping starting from Ti3C2 flakes and demonstrated a better photoactivity than commercially available P25 for hydrogen production (Fig. 7c). The carbon doping also changed the electron structure of TiO2 and enhanced its light absorption ability. Peng et al. [95] also used Ti3C2 as a hole trap and Cu as an electron trap to separate the charges through a dual-carrier-separation mechanism, showing the potential of MXene as an efficient functional material for photocatalysis (Fig. 7d).
Calcination under atmosphere containing gases such as CO2 and O2 is another method used for the controlled oxidation of MXenes (Fig. 8). Lu et al. [96] obtained Ti3C2/TiO2/CuO by annealing Cu(NO3)2 and Ti3C2 together under argon atmosphere (Fig. 8a). Because of its good electronic conductivity, the incorporation of Ti3C2 improved electron/hole separation and led to better methyl orange degradation. Yuan et al. [97] annealed Ti3C2 in CO2 to prepare 2D-layered C/TiO2 hybrids used in hydrogen production, in which the presence of 2D carbon layers increased electron transport channels and enhanced charge separation efficiency (Fig. 8b). In addition, the effects of oxidation temperature and CO2 on the grain size and crystal structure of TiO2 were also investigated, revealing that increasing oxidation temperature and CO2 gas flux led to larger grain sizes and more rutile TiO2 formation. Low et al. [98] calcined Ti3C2 at different temperatures, enabling the in situ growth of TiO2 nanoparticles on Ti3C2 nanosheets, thus forming TiO2/Ti3C2 composites with different loading amounts of TiO2 with the aim to improve performance in CO2 reduction reaction (Fig. 8c). Interestingly, three main products were obtained during the photocatalytic CO2 reduction process due to the sufficiently high intrinsic reduction potential of TiO2. Results of the study also pointed out that excess of Ti3C2 in the composite could have an adverse effect on photocatalytic performance. Su et al. [99] used CO2 to partially oxidize Nb2C to form Nb2O5/Nb2C composites for hydrogen production, where Nb2O5 and metallic Nb2C served, respectively, as the semiconductor photocatalyst and co-catalyst (Fig. 8d). The easily formed junction at the interface served as an electron sink to efficiently capture photogenerated electrons and suppress recombination of photogenerated electron–hole pairs, thus enhancing the efficiency of charge separation and contributing to improved photocatalytic activity [71, 93, 99, 102].
Besides the hydrothermal method and calcination, other routes such as chemical oxidization and high-energy ball milling were also used to oxidize MXenes (Fig. 9). Cheng et al. [100] oxidized Ti3C2 flakes with 30% H2O2 to form microporous-MXene/TiO2−x nanodots (Fig. 9a). This composite worked as a photo-Fenton bifunctional catalyst for Rhodamine B degradation under both dark and illumination conditions. Li et al. [101] synthesized TiO2@C nanosheets from Ti2C by high-energy ball milling and used it for methylene blue degradation (Fig. 9b). Shortly thereafter, our group used water to oxidize Ti3C2 to be applied in hydrogen production using Eosin Y as a sensitizer [102]. Similar to other oxidized MXenes, amorphous carbon and TiO2 were formed after oxidation (Fig. 9c, d). The various MXene-derived composites obtained by in situ oxidation to be used as photocatalysts are listed in Table 1.
The MXenes oxidation is different from other methods because of the residual presence of carbon (mostly amorphous carbon) after oxidation, and the M element is oxidized into metal oxide on the carbon layer. Thus, the composite obtained is of the form metal oxide/MXenes/C. Both MXenes and C can be used as co-catalysts in the photocatalysis process. However, in this method, the ratio of the photocatalyst to MXenes varies within a certain range since no precursor is introduced. The limitation of this method is that only a few semiconductors (depending on M element) can be used as the photocatalyst.
3 Mechanism of MXenes as Co-catalysts
Since MXenes are conductors and serve as co-catalysts, the mechanism of action of a MXenes-based photocatalytic system is through accelerated charge separation and suppression of carrier recombination [69,70,71]. The photocatalysts absorb visible light and photogenerated electrons are excited to the CB, while holes are left in the valence band (VB). The excited charge carriers are transferred to MXenes at the interface mainly because of the higher potential of MXenes. Electrons transfer to MXenes without recombination and react on the MXene surface to generate H2 by reducing H+ [74, 78, 81, 91, 94, 102, 103], CH4 and CO by reducing CO2 [88, 98], or NH3 by reducing N2 [19], as shown in Fig. 10 process (a). In process (b), holes transfer to MXenes and react to produce OH· that can be utilized for degradation of organics [71, 93, 95]; electrons can also produce OH· for organic degradation [71, 93]. The charge transfer process from the photocatalyst to MXenes improves electron–hole pair separation and suppresses charge recombination in photocatalysts, thus enhancing the photoactivity.
Another advantage of using MXenes in photocatalysis is due to their termination groups. For example, –O termination groups show the best potential for hydrogen production because of their low |ΔGH| and the availability of active sites for the adsorption of hydrogen atoms [70, 74]. Though termination groups are important in photocatalysis, currently, it has not been possible to precisely control the relative concentrations of the different termination groups. Using presently available synthetic methods, changing the different reaction conditions can partially modify the termination groups on MXenes surface and thereby affect their performance in photocatalysis.
4 Conclusion and Outlook
In summary, the application of MXenes in photocatalysis has shown rapid development since 2015. Among the MXenes family, Ti3C2 has been the most studied MXene. Mechanical mixing and self-assembly are mild and easy methods of synthesis, where the ratio of MXenes to the photocatalyst can be controlled. In addition, MXenes can also be doped into the photocatalysts by in situ decoration of a semiconductor photocatalyst. The large interfacial area afforded by the doping process improves electron transfer. However, the MXenes oxidation method has the advantage of obtaining both carbon and MXenes as co-catalysts by forming a metal oxide/MXenes/C structure. Though the above-mentioned four synthetic methods are generally used for photocatalysts, with further development in the field of MXenes, new processes may be discovered.
Besides developing improved synthetic methods, the other aspects that need to be focused on in the future are as follows:
- 1.
Controlling the morphologies of MXenes. MXene flakes show larger surface area than multilayered MXenes, since mono- or few-layered MXenes provide a greater number of active sites for photocatalytic reactions. The flakes are also convenient for building structures, such as quantum dots, spheres, and nanorods. However, the instability of MXenes should be taken into account during heat treatment [107].
- 2.
MXenes combine with efficient photocatalysts. MXenes can be used as co-catalysts to combine with many semiconductor photocatalysts due to their excellent electronic conductivity and the presence of numerous hydrophilic groups on the surface. Hundreds of semiconductor photocatalysts have been reported for photocatalysis so far. Attention should be paid to combining the efficient and cheap photocatalysts with MXenes to achieve better photocatalytic performance. So far, only g-C3N4, CdS, ZnS, TiO2, CuO, Nb2O5, BiVO4, Ag3PO4, α-Fe2O3, In2S3, Bi2WO6, Bi0.90Gd0.10Fe0.80Sn0.20O3, and BiOBr have been explored, with TiO2 and g-C3N4 attracting the most attention.
- 3.
Surface modification of MXenes. Surface termination groups significantly affect the properties of MXenes, and thus, tuning the surface termination groups and modifying the MXenes surface are expected to greatly influence its potential as co-catalyst.
- 4.
Synthesis of new MXenes. To date, only a small fraction of the different possible MXenes has been synthesized in laboratories. Some MXenes showing semiconducting properties have been reported based on theoretical calculations. Theoretical predictions help in the synthesis of semiconductor MXenes and applied in photocatalysis. Once obtained experimentally, potential MXenes can be applied as photocatalysts, thus widening the application range of MXenes. Moreover, new types of transition metal borides (MBenes) have also been predicted [34, 109] and have shown potential for photocatalysis applications. More work needs to be done in this direction.
- 5.
Developing new synthesis methods for MXenes. HF and in situ HF wet chemical treatment are by far the most used methods in MXenes synthesis. Other HF-free methods are emerging and leading to MXenes with different properties. Yet, these have not been investigated in photocatalytic applications, and thus, the effect of the type of synthesis process used on the final performance of the MXene is currently not understood.
In short, due to tremendous effort of scientists worldwide, the great potential of MXenes in photocatalysis has been revealed. With the fast-growing development in this area, it is expected that more and more studies will focus on the applications of MXenes photocatalysis and pave the way to the commercialization of photocatalytic technologies based on these materials.
References
M. Naguib, M. Kurtoglu, V. Presser, J. Lu, J. Niu et al., Two-dimensional nanocrystals produced by exfoliation of Ti3AlC2. Adv. Mater. 23, 4248–4253 (2011). https://doi.org/10.1002/adma.201102306
M. Naguib, V.N. Mochalin, M.W. Barsoum, Y. Gogotsi, 25th anniversary article: MXenes: a new family of two-dimensional materials. Adv. Mater. 26, 992–1005 (2014). https://doi.org/10.1002/adma.201304138
B. Anasori, M.R. Lukatskaya, Y. Gogotsi, 2D metal carbides and nitrides (MXenes) for energy storage. Nat. Rev. Mater. 2, 16098 (2017). https://doi.org/10.1038/natrevmats.2016.98
M. Liu, Z. Yang, H. Sun, C. Lai, X. Zhao, H. Peng, T. Liu, A hybrid carbon aerogel with both aligned and interconnected pores as interlayer for high-performance lithium–sulfur batteries. Nano Res. 9, 3735–3746 (2016). https://doi.org/10.1007/s12274-016-1244-1
C. Hou, Z. Tai, L. Zhao, Y. Zhai, Y. Hou et al., High performance MnO@C microcages with a hierarchical structure and tunable carbon shell for efficient and durable lithium storage. J. Mater. Chem. A 6, 9723–9736 (2018). https://doi.org/10.1039/c8ta02863j
B. Kirubasankar, V. Murugadoss, J. Lin, T. Ding, M. Dong et al., In situ grown nickel selenide on graphene nanohybrid electrodes for high energy density asymmetric supercapacitors. Nanoscale 10, 20414–20425 (2018). https://doi.org/10.1039/c8nr06345a
M. Liu, Q. Meng, Z. Yang, X. Zhao, T. Liu, Ultra-long-term cycling stability of an integrated carbon-sulfur membrane with dual shuttle-inhibiting layers of graphene “nets” and a porous carbon skin. Chem. Commun. 54, 5090–5093 (2018). https://doi.org/10.1039/c8cc01889h
W. Du, X. Wang, J. Zhan, X. Sun, L. Kang et al., Biological cell template synthesis of nitrogen-doped porous hollow carbon spheres/MnO2 composites for high-performance asymmetric supercapacitors. Electrochim. Acta 296, 907–915 (2019). https://doi.org/10.1016/j.electacta.2018.11.074
C. Hou, J. Wang, W. Du, J. Wang, Y. Du et al., One-pot synthesized molybdenum dioxide–molybdenum carbide heterostructures coupled with 3D holey carbon nanosheets for highly efficient and ultrastable cycling lithium-ion storage. J. Mater. Chem. A 7, 13460–13472 (2019). https://doi.org/10.1039/c9ta03551f
M. Idrees, S. Batool, J. Kong, Q. Zhuang, H. Liu et al., Polyborosilazane derived ceramics-nitrogen sulfur dual doped graphene nanocomposite anode for enhanced lithium ion batteries. Electrochim. Acta 296, 925–937 (2019). https://doi.org/10.1016/j.electacta.2018.11.088
K. Le, Z. Wang, F. Wang, Q. Wang, Q. Shao et al., Sandwich-like NiCo layered double hydroxide/reduced graphene oxide nanocomposite cathodes for high energy density asymmetric supercapacitors. Dalton Trans. 48, 5193–5202 (2019). https://doi.org/10.1039/c9dt00615j
R. Li, X. Zhu, Q. Fu, G. Liang, Y. Chen et al., Nanosheet-based Nb12O29 hierarchical microspheres for enhanced lithium storage. Chem. Commun. 55, 2493–2496 (2019). https://doi.org/10.1039/c8cc09924c
Y. Ma, C. Hou, H. Zhang, Q. Zhang, H. Liu, S. Wu, Z. Guo, Three-dimensional core-shell Fe3O4/polyaniline coaxial heterogeneous nanonets: Preparation and high performance supercapacitor electrodes. Electrochim. Acta 315, 114–123 (2019). https://doi.org/10.1016/j.electacta.2019.05.073
L. Yang, M. Shi, J. Jiang, Y. Liu, C. Yan, H. Liu, Z. Guo, Heterogeneous interface induced formation of balsam pear-like ppy for high performance supercapacitors. Electrochim. Acta 244, 27–30 (2019). https://doi.org/10.1016/j.matlet.2019.02.064
M. Liu, Y. Liu, Y. Yan, F. Wang, J. Liu, T. Liu, A highly conductive carbon–sulfur film with interconnected mesopores as an advanced cathode for lithium-sulfur batteries. Chem. Commun. 53, 9097–9100 (2017). https://doi.org/10.1039/c7cc04523a
T. Hisatomi, K. Domen, Introductory lecture: sunlight-driven water splitting and carbon dioxide reduction by heterogeneous semiconductor systems as key processes in artificial photosynthesis. Faraday Discuss. 198, 11–35 (2017). https://doi.org/10.1039/c6fd00221h
V.-H. Nguyen, J.C.S. Wu, Recent developments in the design of photoreactors for solar energy conversion from water splitting and CO2 reduction. Appl. Cataly. A Gen. 550, 122–141 (2018). https://doi.org/10.1016/j.apcata.2017.11.002
X. Zhang, Z. Zhang, J. Li, X. Zhao, D. Wu, Z. Zhou, Ti2CO2 MXene: a highly active and selective photocatalyst for CO2 reduction. J. Mater. Chem. A 5, 12899–12903 (2017). https://doi.org/10.1039/c7ta03557h
Q. Liu, L. Ai, J. Jiang, MXene-derived TiO2@C/g-C3N4 heterojunctions for highly efficient nitrogen photofixation. J. Mater. Chem. A 6, 4102–4110 (2018). https://doi.org/10.1039/c7ta09350k
J. Low, J. Yu, M. Jaroniec, S. Wageh, A.A. Al-Ghamdi, Heterojunction photocatalysts. Adv. Mater. 29, 1601694–1601713 (2017). https://doi.org/10.1002/adma.201601694
D. Pan, S. Ge, J. Zhao, Q. Shao, L. Guo, X. Zhang, J. Lin, G. Xu, Z. Guo, Synthesis, characterization and photocatalytic activity of mixed-metal oxides derived from NiCoFe ternary layered double hydroxides. Dalton Trans. 47, 9765–9778 (2018). https://doi.org/10.1039/c8dt01045e
J. Zhao, S. Ge, D. Pan, Q. Shao, J. Lin et al., Solvothermal synthesis, characterization and photocatalytic property of zirconium dioxide doped titanium dioxide spinous hollow microspheres with sunflower pollen as bio-templates. J. Colloid Interface Sci. 529, 111–121 (2018). https://doi.org/10.1016/j.jcis.2018.05.091
Y. Sheng, J. Yang, F. Wang, L. Liu, H. Liu, C. Yan, Z. Guo, Sol-gel synthesized hexagonal boron nitride/titania nanocomposites with enhanced photocatalytic activity. Appl. Surf. Sci. 465, 154–163 (2019). https://doi.org/10.1016/j.apsusc.2018.09.137
J. Tian, Q. Shao, J. Zhao, D. Pan, M. Dong et al., Microwave solvothermal carboxymethyl chitosan templated synthesis of TiO2/ZrO2 composites toward enhanced photocatalytic degradation of Rhodamine B. J. Colloid Interface Sci. 541, 18–29 (2019). https://doi.org/10.1016/j.jcis.2019.01.069
J. Zhao, S. Ge, D. Pan, Y. Pan, V. Murugadoss et al., Microwave hydrothermal synthesis of In2O3-ZnO nanocomposites and their enhanced photoelectrochemical properties. J. Electrochem. Soc. 166, H3074–H3083 (2019). https://doi.org/10.1149/2.0071905jes
H. Shindume, L.Z. Zhao, N. Wang, H. Liu, A. Umar, J. Zhang, T. Wu, Z. Guo, Enhanced photocatalytic activity of B, N-codoped TiO2 by a new molten nitrate process. Electrochim. Acta 19, 839–849 (2019). https://doi.org/10.1166/jnn.2019.15745
Z. Zhao, H. An, J. Lin, M. Feng, V. Murugadoss et al., Progress on the photocatalytic reduction removal of chromium contamination. Chem. Rec. 19, 873–882 (2019). https://doi.org/10.1002/tcr.201800153
G. Zheng, J. Wang, H. Liu, V. Murugadoss, G. Zu et al., Tungsten oxide nanostructures and nanocomposites for photoelectrochemical water splitting. Nanoscale (advance Article, 2019). https://doi.org/10.1039/c9nr03474a
B. Lin, Z. Lin, S. Chen, M. Yu, W. Li et al., Surface intercalated spherical MoS2xSe2(1−x) nanocatalysts for highly efficient and durable hydrogen evolution reactions. Dalton Trans. 48, 8279–8287 (2019). https://doi.org/10.1039/c9dt01218d
T. Su, Q. Shao, Z. Qin, Z. Guo, Z. Wu, Role of interfaces in two-dimensional photocatalyst for water splitting. ACS Catal. 8, 2253–2276 (2018). https://doi.org/10.1021/acscatal.7b03437
M. Ge, J. Cai, J. Iocozzia, C. Cao, J. Huang et al., A review of TiO2 nanostructured catalysts for sustainable H2 generation. Int. J. Hydrog. Energy 42, 8418–8449 (2017). https://doi.org/10.1016/j.ijhydene.2016.12.052
L. Clarizia, D. Russo, I. Di Somma, R. Andreozzi, R. Marotta, Hydrogen generation through solar photocatalytic processes: a review of the configuration and the properties of effective metal-based semiconductor nanomaterials. Energies 10, 1624–1644 (2017). https://doi.org/10.3390/en10101624
X. Zhang, Z. Zhang, Z. Zhou, MXene-based materials for electrochemical energy storage. J. Energy Chem. 27, 73–85 (2018). https://doi.org/10.1016/j.jechem.2017.08.004
Z. Guo, J. Zhou, Z. Sun, New two-dimensional transition metal borides for Li ion batteries and electrocatalysis. J. Mater. Chem. A 5, 23530–23535 (2017). https://doi.org/10.1039/c7ta08665b
H. Jiang, Z. Wang, Q. Yang, L. Tan, L. Dong, M. Dong, Ultrathin Ti3C2T (MXene) nanosheet-wrapped NiSe2 octahedral crystal for enhanced supercapacitor performance and synergetic electrocatalytic water splitting. Nano-Micro Lett. 11, 31 (2019). https://doi.org/10.1007/s40820-019-0261-5
Y.T. Liu, P. Zhang, N. Sun, B. Anasori, Q.Z. Zhu, H. Liu, Y. Gogotsi, B. Xu, Self-assembly of transition metal oxide nanostructures on MXene nanosheets for fast and stable lithium storage. Adv. Mater. 30, 1707334 (2018). https://doi.org/10.1002/adma.201707334
L. Yu, L. Hu, B. Anasori, Y.-T. Liu, Q. Zhu, P. Zhang, Y. Gogotsi, B. Xu, MXene-bonded activated carbon as a flexible electrode for high-performance supercapacitors. ACS Energy Lett. 3, 1597–1603 (2018). https://doi.org/10.1021/acsenergylett.8b00718
H. Liu, X. Zhang, Y. Zhu, B. Cao, Q. Zhu et al., Electrostatic self-assembly of 0D-2D SnO2 quantum dots/Ti3C2Tx MXene hybrids as anode for lithium-ion batteries. Nano-Micro Lett. 11, 65 (2019). https://doi.org/10.1007/s40820-019-0296-7
F. Shahzad, M. Alhabeb, C.B. Hatter, B. Anasori, H.S. Man, C.M. Koo, Y. Gogotsi, Electromagnetic interference shielding with 2D transition metal carbides (MXenes). Science 353, 1137 (2016). https://doi.org/10.1126/science.aag2421
M. Han, X. Yin, X. Li, B. Anasori, L. Zhang, L. Cheng, Y. Gogotsi, Laminated and two-dimensional carbon-supported microwave absorbers derived from MXenes. ACS Appl. Mater. Interfaces 9, 20038–20045 (2017). https://doi.org/10.1021/acsami.7b04602
J. Zhu, E. Ha, G. Zhao, Y. Zhou, D. Huang et al., Recent advance in MXenes: a promising 2D material for catalysis, sensor and chemical adsorption. Coord. Chem. Rev. 352, 306–327 (2017). https://doi.org/10.1016/j.ccr.2017.09.012
A. Sarycheva, A. Polemi, Y. Liu, K. Dandekar, B. Anasori, Y. Gogotsi, 2D titanium carbide (MXene) for wireless communication. Sci. Adv. 4, eaau0920 (2018). https://doi.org/10.1126/sciadv.aau0920
Y. Ying, Y. Liu, X. Wang, Y. Mao, W. Cao, P. Hu, X. Peng, Two-dimensional titanium carbide for efficiently reductive removal of highly toxic chromium(VI) from water. ACS Appl. Mater. Interfaces 7, 1795–1803 (2015). https://doi.org/10.1021/am5074722
N. Liu, N. Lu, Y. Su, P. Wang, X. Quan, Fabrication of g-C3N4/Ti3C2 composite and its visible-light photocatalytic capability for ciprofloxacin degradation. Sep. Purif. Technol. 211, 782–789 (2019). https://doi.org/10.1016/j.seppur.2018.10.027
C. Dall’Agnese, Y. Dall’Agnese, B. Anasori, W. Sugimoto, S. Mori, Oxidized Ti3C2 MXene nanosheets for dye-sensitized solar cells. New J. Chem. 42, 16446–16450 (2018). https://doi.org/10.1039/c8nj03246g
L. Yang, Y. Dall’Agnese, K. Hantanasirisakul, C.E. Shuck, K. Maleski et al., SnO2–Ti3C2 MXene electron transport layers for perovskite solar cells. J. Mater. Chem. A 7, 5635–5642 (2019). https://doi.org/10.1039/c8ta12140k
H.C. Fu, V. Ramalingam, H. Kim, C.H. Lin, X. Fang, H.N. Alshareef, J.H. He, MXene-contacted silicon solar cells with 11.5% efficiency. Adv. Energy Mater. (2019). https://doi.org/10.1002/aenm.201900180
H. Wang, Y. Wu, X. Yuan, G. Zeng, J. Zhou, X. Wang, J.W. Chew, Clay-inspired MXene-based electrochemical devices and photo-electrocatalyst: state-of-the-art progresses and challenges. Adv. Mater. 30, 1704561 (2018). https://doi.org/10.1002/adma.201704561
M. Li, J. Lu, K. Luo, Y. Li, K. Chang et al., Element replacement approach by reaction with lewis acidic molten salts to synthesize nanolaminated MAX phases and MXenes. J. Am. Chem. Soc. 141, 4730–4737 (2019). https://doi.org/10.1021/jacs.9b00574
X. Lu, K. Xu, P. Chen, K. Jia, S. Liu, C. Wu, Facile one step method realizing scalable production of g-c3n4 nanosheets and study of their photocatalytic H2 evolution activity. J. Mater. Chem. A 2, 18924–18928 (2014). https://doi.org/10.1039/c4ta04487h
J. Peng, X. Chen, W.-J. Ong, X. Zhao, N. Li, Surface and heterointerface engineering of 2D MXenes and their nanocomposites: insights into electro- and photocatalysis. Chem 5, 18–50 (2019). https://doi.org/10.1016/j.chempr.2018.08.037
Z.W. Seh, K.D. Fredrickson, B. Anasori, J. Kibsgaard, A.L. Strickler et al., Two-dimensional molybdenum carbide (MXene) as an efficient electrocatalyst for hydrogen evolution. ACS Energy Lett. 1, 589–594 (2016). https://doi.org/10.1021/acsenergylett.6b00247
M. Alhabeb, K. Maleski, T.S. Mathis, A. Sarycheva, C.B. Hatter, S. Uzun, A. Levitt, Y. Gogotsi, Selective etching of silicon from Ti3SiC2 (MAX) to obtain 2D titanium carbide (MXene). Angew. Chem. Int. Ed. 57, 5444–5448 (2018). https://doi.org/10.1002/anie.201802232
J. Xuan, Z. Wang, Y. Chen, D. Liang, L. Cheng et al., Organic-base-driven intercalation and delamination for the production of functionalized titanium carbide nanosheets with superior photothermal therapeutic performance. Angew. Chem. Int. Ed. 128, 14789–14794 (2016). https://doi.org/10.1002/ange.201606643
S. Yang, P. Zhang, F. Wang, A.G. Ricciardulli, M.R. Lohe, P.W.M. Blom, X. Feng, Fluoride-free synthesis of two-dimensional titanium carbide (MXene) using a binary aqueous system. Angew. Chem. Int. Ed. 57, 15491–15495 (2018). https://doi.org/10.1002/anie.201809662
M.R. Lukatskaya, J. Halim, B. Dyatkin, M. Naguib, Y.S. Buranova et al., Room-temperature carbide-derived carbon synthesis by electrochemical etching of MAX phases. Angew. Chem. Int. Ed. 53, 4877–4880 (2014). https://doi.org/10.1002/anie.201402513
S.Y. Pang, Y.T. Wong, S. Yuan, Y. Liu, M.K. Tsang et al., Universal strategy for HF-free facile and rapid synthesis of two-dimensional MXenes as multifunctional energy materials. J. Am. Chem. Soc. 141(24), 9610–9616 (2019). https://doi.org/10.1021/jacs.9b02578
T. Li, L. Yao, Q. Liu, J. Gu, R. Luo et al., Fluorine-free synthesis of high-purity Ti3C2Tx (T = OH, O) via alkali treatment. Angew. Chem. Int. Ed. 57, 6115–6119 (2018). https://doi.org/10.1002/anie.201800887
M. Alhabeb, K. Maleski, B. Anasori, P. Lelyukh, L. Clark, S. Sin, Y. Gogotsi, Guidelines for synthesis and processing of two-dimensional titanium carbide (Ti3C2Tx MXene). Chem. Mater. 29, 7633–7644 (2017). https://doi.org/10.1021/acs.chemmater.7b02847
X. Xiao, H. Wang, P. Urbankowski, Y. Gogotsi, Topochemical synthesis of 2D materials. Chem. Soc. Rev. 47, 8744–8765 (2018). https://doi.org/10.1039/c8cs00649k
V.M. Ng, H. Huang, K. Zhou, P.S. Lee, W. Que, J.Z. Xu, L.B. Kong, Recent progress in layered transition metal carbides and/or nitrides (MXenes) and their composites: synthesis and applications. J. Mater. Chem. A 5(7), 3039–3068 (2017). https://doi.org/10.1039/c6ta06772g
J. Pang, R.G. Mendes, A. Bachmatiuk, L. Zhao, H.Q. Ta et al., Applications of 2D MXenes in energy conversion and storage systems. Chem. Soc. Rev. 48, 72–133 (2019). https://doi.org/10.1039/c8cs00324f
Z. Guo, J. Zhou, L. Zhu, Z. Sun, MXene: a promising photocatalyst for water splitting. J. Mater. Chem. A 4, 11446–11452 (2016). https://doi.org/10.1039/c6ta04414j
S.-Y. Xie, J.-H. Su, H. Zheng, Group-IV analogues of MXene: promising two-dimensional semiconductors. Solid State Commun. 291, 51–53 (2019). https://doi.org/10.1016/j.ssc.2019.01.017
C.-F. Fu, X. Li, Q. Luo, J. Yang, Two-dimensional multilayer M2CO2 (M = Sc, Zr, Hf) as photocatalysts for hydrogen production from water splitting: a first principles study. J. Mater. Chem. A 5, 24972–24980 (2017). https://doi.org/10.1039/c7ta08812d
Z. Guo, N. Miao, J. Zhou, B. Sa, Z. Sun, Strain-mediated type-I/type-II transition in MXene/blue phosphorene van der Waals heterostructures for flexible optical/electronic devices. J. Mater. Chem. C 5, 978–984 (2017). https://doi.org/10.1039/c6tc04349f
J. Cui, Q. Peng, J. Zhou, Z. Sun, Strain-tunable electronic structures and optical properties of semiconducting MXenes. Nanotechnology 30, 345205 (2019). https://doi.org/10.1088/1361-6528/ab1f22
A. Mostafaei, E. Faizabadi, E.H. Semiromi, Theoretical studies and tuning the electronic and optical properties of Zr2CO2 monolayer using biaxial strain effect: modified Becke–Johnson calculation. Physica E 114, 113559 (2019). https://doi.org/10.1016/j.physe.2019.113559
M. Ye, X. Wang, E. Liu, J. Ye, D. Wang, Boosting the photocatalytic activity of P25 for carbon dioxide reduction by using a surface-alkalinized titanium carbide MXene as cocatalyst. Chemsuschem 11, 1606–1611 (2018). https://doi.org/10.1002/cssc.201800083
J. Ran, G. Gao, F.T. Li, T.Y. Ma, A. Du, S.Z. Qiao, Ti3C2 MXene co-catalyst on metal sulfide photo-absorbers for enhanced visible-light photocatalytic hydrogen production. Nat. Commun. 8, 13907 (2017). https://doi.org/10.1038/ncomms13907
C. Peng, X. Yang, Y. Li, H. Yu, H. Wang, F. Peng, Hybrids of two-dimensional Ti3C2 and TiO2 exposing 001 facets toward enhanced photocatalytic activity. ACS Appl. Mater. Interfaces 8, 6051–6060 (2016). https://doi.org/10.1021/acsami.5b11973
X. An, W. Wang, J. Wang, H. Duan, J. Shi, X. Yu, The synergetic effects of Ti3C2 MXene and Pt as co-catalysts for highly efficient photocatalytic hydrogen evolution over g-C3N4. Phys. Chem. Chem. Phys. 20, 11405–11411 (2018). https://doi.org/10.1039/c8cp01123k
X. Xie, N. Zhang, Z.-R. Tang, M. Anpo, Y.-J. Xu, Ti3C2Tx MXene as a Janus cocatalyst for concurrent promoted photoactivity and inhibited photocorrosion. Appl. Catal. B 237, 43–49 (2018). https://doi.org/10.1016/j.apcatb.2018.05.070
Y. Sun, D. Jin, Y. Sun, X. Meng, Y. Gao et al., G-C3N4/Ti3C2Tx (MXenes) composite with oxidized surface groups for efficient photocatalytic hydrogen evolution. J. Mater. Chem. A 6, 9124–9131 (2018). https://doi.org/10.1039/c8ta02706d
T. Cai, L. Wang, Y. Liu, S. Zhang, W. Dong et al., Ag3PO4/Ti3C2 MXene interface materials as a Schottky catalyst with enhanced photocatalytic activities and anti-photocorrosion performance. Appl. Catal. B 239, 545–554 (2018). https://doi.org/10.1016/j.apcatb.2018.08.053
H. Zhang, M. Li, J. Cao, Q. Tang, P. Kang, C. Zhu, M. Ma, 2D a-Fe2O3 doped Ti3C2 MXene composite with enhanced visible light photocatalytic activity for degradation of Rhodamine B. Ceram. Int. 44, 19958–19962 (2018). https://doi.org/10.1016/j.ceramint.2018.07.262
T. Su, Z.D. Hood, M. Naguib, L. Bai, S. Luo et al., Monolayer Ti3C2Tx as an effective co-catalyst for enhanced photocatalytic hydrogen production over TiO2. ACS Appl. Energy Mater. 2, 4640–4651 (2019). https://doi.org/10.1021/acsaem.8b02268
T. Su, Z.D. Hood, M. Naguib, L. Bai, S. Luo et al., 2D/2D heterojunction of Ti3C2/g-C3N4 nanosheets for enhanced photocatalytic hydrogen evolution. Nanoscale 11, 8138–8149 (2019). https://doi.org/10.1039/c9nr00168a
J.-H. Zhao, L.-W. Liu, K. Li, T. Li, F.-T. Liu, Conductive Ti3C2 and MOF-derived CoSx boosting the photocatalytic hydrogen production activity of TiO2. CrystEngComm 21, 2416–2421 (2019). https://doi.org/10.1039/c8ce02050g
R. Chen, P. Wang, J. Chen, C. Wang, Y. Ao, Synergetic effect of MoS2 and MXene on the enhanced H2 evolution performance of CdS under visible light irradiation. Appl. Surf. Sci. 473, 11–19 (2019). https://doi.org/10.1016/j.apsusc.2018.12.071
M. Shao, Y. Shao, J. Chai, Y. Qu, M. Yang et al., Synergistic effect of 2D Ti2C and g-C3N4 for efficient photocatalytic hydrogen production. J. Mater. Chem. A 5, 16748–16756 (2017). https://doi.org/10.1039/c7ta04122e
Y. Xu, S. Wang, J. Yang, B. Han, R. Nie et al., Highly efficient photoelectrocatalytic reduction of CO2 on the Ti3C2/g-C3N4 heterojunction with rich Ti3+ and pyri-N species. J. Mater. Chem. A 6, 15213–15220 (2018). https://doi.org/10.1039/c8ta03315c
Y. Gao, L. Wang, A. Zhou, Z. Li, J. Chen, H. Bala, Q. Hu, X. Cao, Hydrothermal synthesis of TiO2/Ti3C2 nanocomposites with enhanced photocatalytic activity. Mater. Lett. 150, 62–64 (2015). https://doi.org/10.1016/j.matlet.2015.02.135
H. Wang, R. Peng, Z.D. Hood, M. Naguib, S.P. Adhikari, Z. Wu, Titania composites with 2D transition metal carbides as photocatalysts for hydrogen production under visible-light irradiation. Chemsuschem 9, 1490–1497 (2016). https://doi.org/10.1002/cssc.201600165
L. Shi, C. Xu, D. Jiang, X. Sun, X. Wang et al., Enhanced interaction in TiO2/BiVO4 heterostructures via MXene Ti3C2-derived 2D-carbon for highly efficient visible-light photocatalysis. Nanotechnology 30, 075601 (2019). https://doi.org/10.1088/1361-6528/aaf313
Q. Luo, B. Chai, M. Xu, Q. Cai, Preparation and photocatalytic activity of TiO2-loaded Ti3C2 with small interlayer spacing. Appl. Phys. A 124, 495 (2018). https://doi.org/10.1007/s00339-018-1909-6
C. Liu, Q. Xu, Q. Zhang, Y. Zhu, M. Ji et al., Layered BiOBr/Ti3C2 MXene composite with improved visible-light photocatalytic activity. J. Mater. Sci. 54, 2458–2471 (2018). https://doi.org/10.1007/s10853-018-2990-0
S. Cao, B. Shen, T. Tong, J. Fu, J. Yu, 2D/2D heterojunction of ultrathin MXene/Bi2WO6 nanosheets for improved photocatalytic CO2 reduction. Adv. Funct. Mater. 28, 1800136 (2018). https://doi.org/10.1002/adfm.201800136
A. Tariq, S.I. Ali, D. Akinwande, S. Rizwan, Efficient visible-light photocatalysis of 2D-MXene nanohybrids with Gd3+- and Sn4+-codoped bismuth ferrite. ACS Omega 3, 13828–13836 (2018). https://doi.org/10.1021/acsomega.8b01951
H. Wang, Y. Wu, T. Xiao, X. Yuan, G. Zeng et al., Formation of quasi-core-shell In2S3/anatase TiO2 @metallic Ti3C2Tx hybrids with favorable charge transfer channels for excellent visible-light-photocatalytic performance. Appl. Catalysis B 233, 213–225 (2018). https://doi.org/10.1016/j.apcatb.2018.04.012
L. Tie, S. Yang, C. Yu, H. Chen, Y. Liu, S. Dong, J. Sun, J. Sun, In situ decoration of ZnS nanoparticles with Ti3C2 MXene nanosheets for efficient photocatalytic hydrogen evolution. J. Colloid Interface Sci. 545, 63–70 (2019). https://doi.org/10.1016/j.jcis.2019.03.014
T. Wojciechowski, A. Rozmyslowska-Wojciechowska, G. Matyszczak, M. Wrzecionek, A. Olszyna et al., Ti2C MXene modified with ceramic oxide and noble metal nanoparticles: synthesis, morphostructural properties, and high photocatalytic activity. Inorg. Chem. 58, 7602–7614 (2019). https://doi.org/10.1021/acs.inorgchem.9b01015
C. Peng, H. Wang, H. Yu, F. Peng, (111) TiO2−x/Ti3C2: Synergy of active facets, interfacial charge transfer and Ti3+ doping for enhance photocatalytic activity. Mater. Res. Bull. 89, 16–25 (2017). https://doi.org/10.1016/j.materresbull.2016.12.049
G. Jia, Y. Wang, X. Cui, W. Zheng, Highly carbon-doped TiO2 derived from MXene boosting the photocatalytic hydrogen evolution. ACS Sustain. Chem. Eng. 6, 13480–13486 (2018). https://doi.org/10.1021/acssuschemeng.8b03406
C. Peng, P. Wei, X. Li, Y. Liu, Y. Cao et al., High efficiency photocatalytic hydrogen production over ternary Cu/TiO2@Ti3C2Tx enabled by low-work-function 2D titanium carbide. Nano Energy 53, 97–107 (2018). https://doi.org/10.1016/j.nanoen.2018.08.040
Y. Lu, M. Yao, A. Zhou, Q. Hu, L. Wang, Preparation and photocatalytic performance of Ti3C2/TiO2/CuO ternary nanocomposites. J. Nanomater. 2017, 1978764 (2017). https://doi.org/10.1155/2017/1978764
W. Yuan, L. Cheng, Y. Zhang, H. Wu, L. Zheng, 2D layered Carbon/TiO2 hybrids derived from Ti3C2 MXenes for photocatalytic hydrogen evolution under visible light irradiation. Adv. Mater. Interfaces 4, 1700577 (2017). https://doi.org/10.1002/admi.201700577
J. Low, L. Zhang, T. Tong, B. Shen, J. Yu, TiO2/MXene Ti3C2 composite with excellent photocatalytic CO2 reduction activity. J. Catal. 361, 255–266 (2018). https://doi.org/10.1016/j.jcat.2018.03.009
T. Su, R. Peng, Z.D. Hood, M. Naguib, I.N. Ivanov et al., One-step synthesis of Nb2O5/C/Nb2C (MXene) composites and their use as photocatalysts for hydrogen evolution. Chemsuschem 11, 688–699 (2018). https://doi.org/10.1002/cssc.201702317
X. Cheng, L. Zu, Y. Jiang, D. Shi, X. Cai, Y. Ni, S. Lin, Y. Qin, A titanium-based photo-fenton bifunctional catalyst of mp-MXene/TiO2−x nanodots for dramatic enhancement of catalytic efficiency in advanced oxidation processes. Chem. Commun. 54, 11622–11625 (2018). https://doi.org/10.1039/c8cc05866k
J. Li, S. Wang, Y. Du, W. Liao, Enhanced photocatalytic performance of TiO2@C nanosheets derived from two-dimensional Ti2CTx. Ceram. Int. 44, 7042–7046 (2018). https://doi.org/10.1016/j.ceramint.2018.01.139
Y. Sun, Y. Sun, X. Meng, Y. Gao, Y. Dall’Agnese et al., Eosin Y-sensitized partially oxidized Ti3C2 MXene for photocatalytic hydrogen evolution. Catal. Sci. Technol. 9, 310–315 (2019). https://doi.org/10.1039/c8cy02240b
Y. Li, X. Deng, J. Tian, Z. Liang, H. Cui, Ti3C2 MXene-derived Ti3C2/TiO2 nanoflowers for noble-metal-free photocatalytic overall water splitting. Appl. Mater. Today 13, 217–227 (2018). https://doi.org/10.1016/j.apmt.2018.09.004
W. Yuan, L. Cheng, Y. An, S. Lv, H. Wu, X. Fan, Y. Zhang, X. Guo, J. Tang, Laminated hybrid junction of sulfur-doped TiO2 and a carbon substrate derived from Ti3C2 MXenes: toward highly visible light-driven photocatalytic hydrogen evolution. Adv. Sci. 5, 1700870 (2018). https://doi.org/10.1002/advs.201700870
A. Shahzad, K. Rasool, M. Nawaz, W. Miran, J. Jang et al., Heterostructural TiO2/Ti3C2Tx (MXene) for photocatalytic degradation of antiepileptic drug carbamazepine. Chem. Eng. J. 349, 748–755 (2018). https://doi.org/10.1016/j.cej.2018.05.148
Y. Li, Z. Yin, G. Ji, Z. Liang, Y. Xue et al., 2D/2D/2D heterojunction of Ti3C2 MXene/MoS2 nanosheets/TiO2 nanosheets with exposed (001) facets toward enhanced photocatalytic hydrogen production activity. Appl. Catal. B 246, 12–20 (2019). https://doi.org/10.1016/j.apcatb.2019.01.051
C.J. Zhang, S. Pinilla, N. McEvoy, C.P. Cullen, B. Anasori et al., Oxidation stability of colloidal two-dimensional titanium carbides (MXenes). Chem. Mater. 29, 4848–4856 (2017). https://doi.org/10.1021/acs.chemmater.7b00745
M. Sharma, S. Vaidya, A.K. Ganguli, Enhanced photocatalytic activity of g-C3N4-TiO2 nanocomposites for degradation of Rhodamine B dye. J. Photochem. Photobiol. A 335, 287–293 (2017). https://doi.org/10.1016/j.jphotochem.2016.12.002
L.T. Alameda, P. Moradifar, Z.P. Metzger, N. Alem, R.E. Schaak, Topochemical deintercalation of Al from MoAlB: stepwise etching pathway, layered intergrowth structures, and two-dimensional MBene. J. Am. Chem. Soc. 140, 8833–8840 (2018). https://doi.org/10.1021/jacs.8b04705
Acknowledgements
This work was supported by the National Natural Science Foundation of China (No. 11574111 and No. 11974129 to X.-F. W.) and “the Fundamental Research Funds for the Central Universities.”
Author information
Authors and Affiliations
Corresponding authors
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Sun, Y., Meng, X., Dall’Agnese, Y. et al. 2D MXenes as Co-catalysts in Photocatalysis: Synthetic Methods. Nano-Micro Lett. 11, 79 (2019). https://doi.org/10.1007/s40820-019-0309-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s40820-019-0309-6