Insights into the Operation of Noble-Metal-Free Cocatalyst 1T-WS -Decorated Zn Cd S for Enhanced Photocatalytic Hydrogen Evolution.

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