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2D Materials for Flexible Photo Detector Applications
Published in Ram K. Gupta, 2D Nanomaterials, 2022
Aruna Pattipati, Joseph Chennemkeril Mathew
Recently buckled Graphene analogues (Xenes) have created interest among researchers and are being studied theoretically for their usage in flexible nanoelectronics [30]. MXenes are a new type of 2D material composed of elements Mn+1XnTx elements where M is a transition metal element, X is Carbides or Nitrides and T is a group or modification on the surface of the 2D material and n takes the value in the range 1–3. MXenes have the advantages like good optical transmittance, fast charge transfer, tunable bandgap, more active sites, ease of modification and low cost of fabrication [31]. Currently most of the MXenes exhibit metal-like properties with small bandgaps [32] and provide a platform for photon electron coupling on the surface. Hence they are widely used in biological, chemical and optical sensors [32]. Room temperature solid-state properties of selected 2D crystalline materials are mentioned in a previous report [9].
2 Reduction
Published in Zuzeng Qin, Tongming Su, Hongbing Ji, MXene-Based Photocatalysts, 2022
MXenes are prepared by etching the MAX phase with various etchant, such as HF and LiF/HCl. Therefore, different functional groups were generated on the surface of MXene (–OH, –F, –O, etc.) (Ghidiu et al. 2014). The surface chemical property of MXenes is closely related to the surface-functional groups. For example, surface-terminal groups can provide a large number of active sites for the CO2 adsorption and reaction, which inspired researchers to modify the surface-termination groups of MXenes to obtain the highly active catalyst. So far, the synthesis of MXenes with uniform and pure surface-termination groups is still an experimental challenge. MXene with mixed functional groups has attracted great attention.
MXene as a 2D Material for the Surface Plasmon Resonance Sensing
Published in Sanjeev Kumar Raghuwanshi, Santosh Kumar, Yadvendra Singh, 2D Materials for Surface Plasmon Resonance-based Sensors, 2021
Sanjeev Kumar Raghuwanshi, Santosh Kumar, Yadvendra Singh
MXenes can be synthesized through specific acid etching of MAX or non-MAX parents (typically from the periodic table groups 13 and 14), chemical transformations, either bottom-up construction techniques. In terms of viability, yields, controllability, and cost-effectiveness, the first approach currently outperforms the others. MAX ternary carbides and nitrides occur in over 70 various configurations (Anasori, Lukatskaya, and Gogotsi 2017), indicating that the MXene family has a great deal of diversity. Experiments have yielded over 30 different types of MXenes, with many more predicted based on theoretical predictions (Frey et al. 2019; Pan, Lany, and Qi 2017). Fig. 5.15 depicts a brief timeline of the growth of MXenes.
Bismuth oxide modified V2C MXene as a Schottky catalyst with enhanced photocatalytic oxidation for photo-denitration activities
Published in Environmental Technology, 2022
Ran Zhao, Junyi Liu, Yahui Nie, Hanmei Wang
MXene is a new class of 2D environment-friendly photocatalyst with favourable photocatalytic properties. Owing to the unique multilayer structure, MXenes have a wide chemical and structural variety, which makes them competitive with other 2D materials. Up to date, over 20 different MXene materials have been proposed. The availability of solid solutions, the control of surface terminations, and a recent discovery of multi-transition-metal layered MXenes offer the potential for the synthesis of many new structures. As shown in Table S1, the V2C based catalysts have been proved as a promising matrix for applications including dye degradation [5], hydrogen evolution [6,7], white lasers [8], supercapacitor [9,10], ion storage [11], and lithium–sulfur batteries [12,13]. Other attractive electronic, optical, plasmonic, and thermoelectric properties have also been shown [14]. According to a recent theoretical study, V2C MXene has the potential to be an effective catalyst, which offers an inexpensive and efficient alternative to precious metals. However, MXene material is not usually used as a single photocatalyst due to its rapid recombination of photogenerated carriers and easy particle aggregation. To the best of our knowledge, there are few studies on photocatalytic NO pollutant removal by V2C MXexe-based catalyst. Also, the utilization of the V2C MXene to activate the bismuth-based catalyst for denitration has never been reported so far.
Two-dimensional materials beyond graphene for the detection and removal of antibiotics: A critical review
Published in Critical Reviews in Environmental Science and Technology, 2022
Lingxia Lu, Qi Yang, Qing Xu, Yongjun Sun, Susu Tang, Xiaobin Tang, Heng Liang, Yadong Yu
The chemical formula of MXenes is Mn+1AXn in which “n” ranges from 1 to 3. “M” indicates early transition metals (Cr, Mo, Nb, Sc, Ti, V or Zr), “A” represents the third or fourth main group of chemical elements, and “X” indicates C or N (Figure 3G) (Fard et al., 2017). Many MXenes are produced by selectively etching atomic layers away from their precursors. The properties of MXenes are determined by the precursor, etching method, etchant, and intercalation method (Jun et al., 2019). MXenes have many remarkable properties, such as high electrical conductivity, good optical transparency, and clay-like behavior, which render them suitable for various applications (Verger et al., 2019). Recently, researchers have employed MXenes as co-catalysts for the photocatalytic degradation of antibiotics (Cao et al., 2020; Shen et al., 2019).
Enhanced ethanol response of Ti3C2TX MXene derivative coupled with NiO nanodisk
Published in Inorganic and Nano-Metal Chemistry, 2022
Zhigang Shao, Zhihua Zhao, Pu Chen, Jinzhou Chen, Wentao Liu, Xiaoqing Shen, Xuying Liu
MXenes, as a large family of two-dimensional (2 D) transition metal carbides and nitrides, were firstly reported in 2011 by selectively etching out the A group (generally group IIIA and IVA elements) from the layered ternary precursors MAX phase. The chemical formula of MXenes is Mn+1XnTx, where M represents a nearly transition metal, X represents carbon/nitrogen (C/N), with n = 1, 2, or 3, Tx represents various O, OH, and F surface functional groups. MXenes exhibit good flexibility, large specific surface area and high metallic conductivity like some other 2 D materials as graphene, transition metal dichalcogenides, and hexagonal boron nitrides. Meanwhile, MXenes possess rich surface chemistry and other excellent characteristics like fascinating mechanical, optical, electronic, and thermal properties, which make MXenes became one of the most famous candidates for the application of photo/electro catalysts, energy storage, water purification, electromagnetic interference shielding, and sensors.[27,28]