Insights into the Operation of Noble‐Metal‐Free Cocatalyst 1T‐WS<sub>2</sub>‐Decorated Zn<sub>0.5</sub>Cd<sub>0.5</sub>S for Enhanced Photocatalytic Hydrogen Evolution
Zhiqiang Li, Wei Zhou, Yuan Tang, Xin Tan, Yizhong Zhang, Zikang Geng, Yu-Chen Guo, Lequan Liu, Tao Yu, Jinhua Ye
Abstract
Abstract 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 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 containing 7.5 % 1T‐WS 2 in 1T‐WS 2 /Zn 0.5 Cd 0.5 S achieves a hydrogen evolution rate of 61.65 mmol g −1 h −1 and an external quantum efficiency of 8.04 % at 420 nm, which is 37 times 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 different Fermi levels of 1T‐WS 2 and Zn 0.5 Cd 0.5 S form a Schottky junction, which promotes the transfer 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 interactions, 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.