A Z-scheme Pd modified ZnIn2S4/P25 heterojunction for enhanced photocatalytic hydrogen evolution

Pd modified ZnIn 2 S 4 /P25 (Pd@ZnIn 2 S 4 /P25) heterostructures have been synthesized by hydrothermal and photo-reduction method. The H 2 evolution rate of optimal photocatalyst 0.5 %Pd modified 5ZnIn 2 S 4 /2P25 (0.5 %Pd@5ZnIn 2 S 4 /2P25) are approximately 9100 and 3693 μmol · g −1 h −1 under simulated sunlight and visible light irradiation with ethanol as the sacrificial agent, which are nearly 9 and 460 times higher than pure ZnIn 2 S 4 and P25, respectively. The promoted photocatalytic performance can be attributed to the physicochemical properties of the catalysts and the strong electronic interaction between Pd modified ZnIn 2 S 4 (Pd@ZnIn 2 S 4 ) and P25, the improved transfer rate of photo-generated electrons and holes, the inhibited recombination of charge carriers, and the enhanced light harvesting. The results of photo-electrochemistry and EPR indicate that it is a Z-scheme photocatalytic system, in which the electrons accumulate on the conduct band of ZnIn 2 S 4 and the holes assemble on the valence band of P25. This work provides an effective method to construct highly efficient photocatalytic systems for solar H 2 generation.