Direct Observation of Z‐Scheme Route in Cu₃₁S₁₆/Zn_xCd_1‐xS Heteronanoplates for Highly Efficient Photocatalytic Hydrogen Evolution

AbstractAlthough photocatalytic hydrogen production from water holds great potential as a renewable and sustainable energy alternative, the practical application of the technology demands cost‐effective, simple photocatalytic systems with high efficiency in hydrogen evolution reaction (HER). Herein, the synthesis and characterization of Cu31S16/ZnxCd1‐xS heterostructured nanoplates (Cu31S16/ZnCdS HNPs) as a high photocatalytic system are reported. The cost‐effective, hierarchical structures are easily prepared using the Cu31S16 NPs as the seed by the epitaxial growth of the ZnCdS nanocrystals (NCs). The Cu31S16/ZnCdS without the noble metal cocatalyst exhibits a high HER rate of 61.7 mmol g−1 h−1, which is 8,014 and 17 times higher than that of Cu31S16 and ZnCdS, respectively, under visible light irradiation. The apparent quantum yield (AQY) of Cu31S16/ZnCdS reaches 67.9% at 400 nm with the highest value so far in the reported ZnCdS‐based photocatalysts. The excellent activity and stability of the Cu31S16/ZnCdS are attributed to the formation of a strong internal electric field (IEF) and the Z‐scheme pathway. The comprehensive experiments and theoretical calculations provide the direct evidences of the Z‐scheme route. This work may offer a way for the design and development of efficient photocatalysts to achieve solar‐to‐chemical energy conversion at a practically useful level.