In situ growth of 1T-WS2 on ultrathin Ti3C2Tx as a hybrid cocatalyst for enhancing the photocatalytic activity of CdS

Abstract

Accelerating charge transfer and separation is the core mission of promoting photocatalytic H2 production activity. Here, the hybrid cocatalyst Ti3C2Tx/1T-WS2 is synthesized by in situ growth of 1T-WS2 on the ultrathin Ti3C2Tx surface using a solvothermal method for enhancing the photocatalytic activity of CdS. The difference in CB potentials between CdS and 1T-WS2 results in the rapid migration of photogenerated electrons from CdS to 1T-WS2. More importantly, because of the intimate Schottky interfacial contact between Ti3C2Tx and 1T-WS2, the electrons on the 1T-WS2 further rapidly transfer to the surface of Ti3C2Tx, thereby enhancing the separation efficiency of photogenerated electrons. Compared with the single Ti3C2Tx (4.66 mmol∙g−1∙h−1) and 1T-WS2 (10.65 mmol∙g−1∙h−1), the hybrid Ti3C2Tx/1T-WS2 cocatalyst (12.39 mmol∙h−1∙g−1) has more excellent catalytic hydrogen evolution performance. The apparent quantum efficiency (AQE) Ti3C2Tx/1T-WS2/CdS at λ = 420 nm reaches 50.9%. This work is helpful to understand the mechanism of the hybrid cocatalyst to improve charge separation.