Ti₃C₂T _x MXene anchoring semi-metallic selenium atoms: self-powered photoelectrochemical-type photodetector, hydrogen evolution, and gas-sensing applications

Abstract

MXenes have demonstrated substantial promise as photocatalysts and electrocatalysts for a variety of applications such as self-powered photoelectrochemical (PEC)-type photodetector, hydrogen evolution reaction (HER), and vapor sensing applications. However, their mechanism is still poorly figured out. Currently, Ti3C2Tx MXene suffers from low photoresponsivity, high overpotential, and low sensitivity in such important applications. In order to develop catalytic activity and performances of those devices, modifications must be made to the structure of MXenes to enhance the separation of photogenerated charges, rate of the H+/e- couplings, and surface-active sites. These manipulations of MXenes heavily depend on understanding the mechanism of devices, appropriate modification elements, and the method of modification. This study for the first time reveals a facile solid-state annealing strategy for doping semi-metallic selenium (Se) atoms on Ti3C2Tx MXene for self-powered PEC-type photodetector, HER, and vapor sensor applications. The suitable characteristics of Ti3C2Tx make it an appropriate substrate to accommodate Se atoms. The well-designed Se-doped Ti3C2 heterojunction including some TiO2 cuboids could exhibit unprecedented photoresponsivity (up to 90 mA W-1) and detectivity (up to 2.0×108 cm Hz1/2 W-1) for 420 nm light, HER (- 0.7 V at 10 mA cm-2), and gas sensitivity (Z’ = 347 Ω and Z” = 150 Ω, for ethanol) in comparison with the pristine Ti3C2Tx nanosheets. The acquired promising results can be promoted with some other elements and also be examined in other electrolytes. Then, bring inspiration to the applications involving charge transfer, H+/e- couplings, and surface-active sites.

Chalcogen (S, Se, and Te) decorated few-layered Ti3C2Tx MXene hybrids: modulation of properties through covalent bonding

“…4a-c). 33 It can be observed that the responsivity of the Te/Ti 3 C 2 T x sample (Fig. 5a) reaches 70 μA W −1 which is almost 20 times higher than the responsivity of blank few-layered Ti 3 C 2 T x (Fig.…”

“…Similar results have been observed in single Se atoms on Ti 3 C 2 T x MXene nanosheets under CO 2 conditions, 26 as well as in our other recent work by the solid-state annealing method. 33 This variation would be due to the substitution in termination contents by chalcogen elements and oxygen-containing terminations (like Ti–O, C–O, S–O, and Se–O). High-resolution XPS spectra of the elements of the samples can further help evaluate the changes in chemical states and their occupancy after decoration of the few-layered Ti 3 C 2 T x MXene with Te, Se, and S (Fig.…”

Powering the Future: Unleashing the Potential of MXene‐Based Dual‐Functional Photoactive Cathodes in Photo‐Rechargeable Zinc‐Ion Capacitor

“…[21] The formation of a greater TiO 2 anatase phase in Te/Ti 3 C 2 T x is due to oxygen-containing species and a fraction of fluorine surface terminations on Ti 3 C 2 T x , which are well-known for stabilizing TiO 2 anatase. [29,34] Raman characterizations show that the vibrational modes of Ti 3 C 2 T x are at three main bonds of A 1g (Ti atoms at ≈210 cm −1 , TiO 2 at ≈500 cm −1 , C atoms at ≈625 cm −1 , and C─C at ≈700 cm −1 ), E g (TiO 2 at ≈130 cm −1 , O atoms, ≈376 cm −1 ) and H atoms at ≈255 cm −1 . An additional band in the Te/Ti 3 C 2 T x sample was detected, attributed to the vibration and translational modes of the Te (A 1g at ≈120 cm −1 ).…”

A New, Thorough Look on Unusual and Neglected Group III‐VI Compounds Toward Novel Perusals

“…[68] For instance, the properties shown by 2D semiconductors are yet interesting for an increasingly large market slice, and despite all the aforementioned challenges, preparing and manipulating high-quality 2D materials is still developing. [13,68] Chemically 2D materials present a wide range of categorizes of oxides, [69][70][71] carbon-based, [61,72,73] element-based (borophene, [74,75] black phosphorus, [48] silicene, [76,77] germanene, [78,79] antimonene, [56,80] stanene, [79,[81][82][83][84] ), carbides and nitrides of transition metal (MXenes, [85,86] ) and metal chalcogenides. In the case of the last family of 2D materials, the most studied are the transition metal dichalcogenides (MoS 2 , [62,64] WS 2 , WSe 2 , and WTe 2 [87] ) and the various group of III-V, [88] and III-VI chalcogenides.…”

“…Chemically 2D materials present a wide range of categorizes of oxides, [ 69–71 ] carbon‐based, [ 61,72,73 ] element‐based (borophene, [ 74,75 ] black phosphorus, [ 48 ] silicene, [ 76,77 ] germanene, [ 78,79 ] antimonene, [ 56,80 ] stanene, [ 79,81–84 ] ), carbides and nitrides of transition metal (MXenes, [ 85,86 ] ) and metal chalcogenides. In the case of the last family of 2D materials, the most studied are the transition metal dichalcogenides (MoS 2 , [ 62,64 ] WS 2 , WSe 2 , and WTe 2 [ 87 ] ) and the various group of III‐V, [ 88 ] and III‐VI chalcogenides.…”