Zn0.8Cd0.2S Photocatalyst Modified with Ni(OH)2 for Enhanced Photocatalytic Hydrogen Production

Sustainable production of hydrogen is currently a global research hotspot. In this study, a Ni(OH)2 cocatalyst was loaded on Zn0.8Cd0.2S to form Ni(OH)2/ZCS composites and achieve highly efficient photocatalytic hydrogen production. After Ni(OH)2 loading, a close contact interface was established between Ni(OH)2 and Zn0.8Cd0.2S, which increased the separation efficiency of the photogenerated electrons and holes. Moreover, the addition of Ni(OH)2 increases the specific surface area and light absorption of Ni(OH)2/Zn0.8Cd0.2S, and the Ni(OH)2 can act as active sites for photocatalytic hydrogen production. The photocatalytic H2 production rate of Ni(OH)2/ZCS composites increases with the increase in the Ni amount. 9Ni(OH)2/ZCS exhibited the optimum H2 production rate of 12.88 mmol h−1 g−1, which was 9.9 times higher than that of Zn0.8Cd0.2S. When the amount of Ni(OH)2 is further increased, the excess Ni(OH)2 covers the active site of Zn0.8Cd0.2S and reduced the light absorption of Zn0.8Cd0.2S, resulting in a decrease in the H2 production rate. Furthermore, the H2 production rate of 9Ni(OH)2/ZCS decreased from 12.88 to 5.15 mmol g−1 h−1 after 3 cycles. The main reason for the decline in the photocatalytic performance of Ni(OH)2/ZCS is the photocorrosion of Zn0.8Cd0.2S. This study provides an innovative design for loading Ni(OH)2 cocatalysts on Zn0.8Cd0.2S to improve the performance of photocatalysts.