Photocatalytic Activity of Twist-Angle Stacked 2D TaS2

Abstract

The development of low-cost efficient photoelectrosensitive electrodes as an alternative to the expensive and complex rigid systems is yet in huge demand for advanced photoresponsive technology. Herein, the light-induced efficiency of electrochemically exfoliated TaS2 nanosheets for hydrogen generation catalysis and photodetectors has been demonstrated for the first time. The electrochemical exfoliation of TaS2 crystals toward a few-layer derivative has been pioneered in anhydrous tetrabutylammonium hexafluorophosphate in N, N-dimethylformamide. Comprehensive analysis of as-exfoliated TaS2 revealed the formation of nanoparticles and nanosheets with a lateral size of about several nanometers and micrometers, correspondingly. Observed mutual twisting of 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 catalyst demonstrates high HER photoelectrocatalytic activity with the onset overpotential below 575 mV vs. RHE which can be lowered by thorough catalyst preparation. Finally, the TaS2-integrated photodetector in the acidic medium represents its broadband light sensing capability with the highest photoresponsivity (0.68 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