Photocatalytic activity of twist-angle stacked 2D TaS2

Abstract

The low-cost, efficient photoelectrosensitive electrodes as an alternative to expensive and complex rigid systems are yet in demand for advanced photoresponsive technology. Here, the light-induced efficiency of electrochemically exfoliated TaS2 nanosheets for hydrogen generation catalysis and photodetectors was demonstrated. Mutual twisting of the exfoliated 2H-TaS2 flakes leads to the redistribution of charge density induced by interlayer interaction of the individual nanosheets. External light irradiation on the TaS2 surface influences its conductivity making the material feasible for photoelectrocatalysis and photodetection. The TaS2-based photoelectrocatalyst demonstrates high hydrogen evolution reaction (HER) activity with the onset overpotential below 575 mV vs. reversible hydrogen electrode (RHE). The TaS2-integrated photodetector in the acidic medium represents its broadband response with the highest photoresponsivity (0.62 mA W−1) toward 420 nm light illumination. This finding will pave the way to a new realization of exfoliated twist-angle stacked TaS2 for photo-induced electrochemistry and sensing.

Beyond the Platinum Era─Scalable Preparation and Electrochemical Activation of TaS2 Flakes

“…In turn, the TEM and HRTEM images (Figure C–F) confirm the typical flake morphology. From the images, the d-spacings were determined to be 0.33 nm for 3R-TaS 2 and 0.29 nm for 1T-TaS 2 , both in agreement with the previously published results. ,, Finally, the results of electron diffraction confirm the good crystallinity of both 3R-TaS 2 and 1T-TaS 2 flakes (Figure S7).…”

“…Changes in the peak positions between the 3R and 1T phases were observed and are shown in Figure S1. Similar peak positions were reported in the literature for the 3R , and 1T ,, phases. Raman spectroscopy also confirms that the sulfurization of Ta 2 O 5 takes place at temperatures above 600 °C (Figure B), thus supporting the results of X-ray diffraction analysis.…”

Engineering Vacancies at the 2D Nanocrystals for Robust Bifunctional Electrocatalysts

“…A platinum electrode was applied to the anode, and an acetonitrile solution of quaternary ammonium salt was used as the electrolyte at a concentration of 5 mM. The electrochemical intercalation voltage was 5–10 V, and the time was 1 h. − In the process of electrochemical intercalation, a negative voltage is applied to the tantalum sulfide crystal, and quaternary ammonium cation (THA + ) with a positive charge is inserted into the tantalum sulfide crystal layer driven by negative potential so that the layer spacing becomes larger and tantalum sulfide crystal expands. The structure (such as layer spacing and molecular packing density) and properties (electron doping level) of intercalated compounds are adjusted by adjusting the size of intercalated molecules.…”

InSe:Ge-doped InSe van der Waals heterostructure to enhance photogenerated carrier separation for self-powered photoelectrochemical-type photodetectors

“…6,7 Two-dimensional (2D) materials with a single to a few atomic layers exhibit unique photoelectric conversion efficiencies and high sensitivity; for example, black phosphorus, hexagonal boron nitride, transition metal dichalcogenides (TMDs), and post-transition metal dichalcogenides have been rapidly applied to photodetectors to achieve competitive photoelectric performance. 8–10…”