Enhanced Visible‐Light Hydrogen‐Production Activity of Copper‐Modified Zn x Cd 1− x S

Copper modification is an efficient way to enhance the photocatalytic activity of ZnS‐based materials; however, the mechanisms of Cu 2+ surface and bulk modifications for improving the activity are quite different. In this work, two different synthetic pathways were devised to prepare surface and bulk Cu 2+ ‐modified Zn x Cd 1− x S photocatalysts through cation‐exchange and coprecipitation methods, respectively. Different Cu 2+ modifications brought different effects on the phase structure, morphology, surface area, optical property, as well as the photocatalytic H 2 ‐production activity of the final products. The optimized Cu 2+ ‐surface‐modified Zn x Cd 1− x S photocatalyst has a high H 2 ‐production rate of 4638.5 μmol h −1  g −1 and an apparent quantum efficiency of 20.9 % at 420 nm, exceeding that of Cu 2+ ‐bulk‐modified catalyst at the same copper content. Cu 2+ surface modification not only brings a new electron‐transferring pathway (interfacial charge transfer), but also produces new surface active sites for H 2 evolution, reducing the recombination rate of photogenerated charge carriers.