Insights into the Function of Noble-Metal-Free Cocatalyst 1T-WS2 Decorated Zn0.5Cd0.5S for Enhanced the Photocatalytic Hydrogen Evolution

Due to the seriously inefficient charge separation and surface catalytic conversion efficiency, cocatalyts are fundamentally required for photocatalytic hydrogen evolution. Being a noble-metal-free cocatalyst, metallic 1T-WS 2 with excellent conductivity can function for this reaction. Herein, 1T-WS 2 /Zn 0.5 Cd 0.5 S is constructed via a simple and feasible grinding approach, the composite accompanied with 7.5% 1T-WS 2 of in 1T-WS 2 /Zn 0.5 Cd 0.5 S, achieves hydrogen evolution rate of 61.65mmol g -1 h -1 and with external quantum efficiency of 8.04% at 420 nm, which is 37 times than that of bare Zn 0.5 Cd 0.5 S (1.67 mmol g -1 h -1 ). The electrical conductivity of metallic 1T-WS 2 reduces the transfer impedance at the interface and thus accelerates the non-radiative energy transfer and electron transport rate. The difference Fermi levels of 1T-WS 2 and Zn 0.5 Cd 0.5 S forms Schottky junction, promotes the transformation of photogenerated electrons from Zn 0.5 Cd 0.5 S to 1T-WS 2 . More importantly, the close interface contact between 1T-WS 2 and Zn 0.5 Cd 0.5 S results in strong electron interaction, which is conducive to the spatial separation of photogenerated electrons and holes. This work will further expand the application of 1T-WS 2 in the photocatalytic hydrogen evolution process.