Growing ZnIn2S4 nanosheets on FeWO4 flowers with p-n heterojunction structure for efficient photocatalytic H2 production

Abstract

Constructing heterojunction structure can efficiently accelerate the separation and transfer of charge carriers and improve the photoactivity. Herein, a high-performance FeWO4/ZnIn2S4 composite with abundant and tight 2D/2D hetero-interfaces was rational designed and prepared. ZnIn2S4 nanosheets as hydrogen evolution species uniformly grow on the surface of FeWO4 flower, constructing a unique face-to-face hierarchical architecture. A maximum H2 production rate of 3531.2 μmol h−1 g−1 was obtained at the optimal mass ratio of FeWO4 to ZnIn2S4, which was 35 times higher than pure ZnIn2S4. Based on the experimental results and the Density Functional Theoretical calculation results, a possible p-n heterojunction mechanism and the transfer route of photoinduced charges toward the improved H2 production were proposed. The p-n heterojunction between FeWO4 and ZnIn2S4 nanosheets plays a key role in enhancing photocatalytic H2 production activity. Moreover, the intimate interface between two components and the preferable hydrophilic property favors the improved H2 evolution rate.