Rational design of Au decorated Mn0.5Cd0.5S/WO3 step-scheme heterostructure with multichannel charge transfer and efficient H-2 generation

Spontaneously solar-driven H-2-production from water reduction provides a promising strategy to solve the ag-gravating energy and environment crises worldwide, but it is severely limited by the rapid charge-carrier re-combination and the slashing redox potentials requirement. Here, a new ternary Mn0.5Cd0.5S/WO3/Au hetero-structure photocatalyst has been designed by chemical deposition of Au nanoparticles (NPs) on Mn0.5Cd0.5S/WO3 step-scheme (S-scheme) composite matrix to boost the photocatalytic activity through the multichannel-enhanced charge transfer/separation. By optimizing the constituent of the heterostructure photocatalyst, the prepared Mn0.5Cd0.5S/WO3/Au photocatalyst with 30 wt% of WO3 and 4 wt% of Au exhibits the highest H-2-evolution rate of 517.13 mu mol h(-1) under simulated solar light irradiation, more 2.74, 1.63 and 1.45 times higher than bare Mn0.5Cd0.5S and Mn0.5Cd0.5S loaded with WO3 and Au alone, respectively. Mechanistic character-izations and control experiments have revealed that the S-scheme charge transfer in Mn0.5Cd0.5S/WO3 hetero-junction together with the electron reservoir resulting from the Au NPs contribute to the superior H-2-gen-eration activity over Mn0.5Cd0.5S/WO3/Au catalyst, which not only dramatically promotes the charge-carrier separation but also remains the strong redox ability of photoinduced electrons and holes in such photocatalytic system.