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

A face-to-face FeWO 4 /ZnIn 2 S 4 photocatalyst with p-n heterojunction structure was prepared via an in-situ of growth route toward efficient photocatalytic H 2 evolution. • FeWO 4 /ZnIn 2 S 4 composite were prepared via an in-situ of growth process. • The composite shows about 35 times higher than the photoactivity of ZnIn 2 S 4 . • The formed built-in field from p-n heterojunctions boosts the charge separation. • Based on experimental and DFT results, the photocatalytic mechanism was proposed. Constructing heterojunction structure can efficiently accelerate the separation and transfer of charge carriers and improve the photoactivity. Herein, a high-performance FeWO 4 /ZnIn 2 S 4 composite with abundant and tight 2D/2D hetero-interfaces was rational designed and prepared. ZnIn 2 S 4 nanosheets as hydrogen evolution species uniformly grow on the surface of FeWO 4 flower, constructing a unique face-to-face hierarchical architecture. A maximum H 2 production rate of 3531.2 μmol h −1 g −1 was obtained at the optimal mass ratio of FeWO 4 to ZnIn 2 S 4 , which was 35 times higher than pure ZnIn 2 S 4 . 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 H 2 production were proposed. The p-n heterojunction between FeWO 4 and ZnIn 2 S 4 nanosheets plays a key role in enhancing photocatalytic H 2 production activity. Moreover, the intimate interface between two components and the preferable hydrophilic property favors the improved H 2 evolution rate.