Highly efficient white-LED-light-driven photocatalytic hydrogen production using highly crystalline ZnFe2O4/MoS2 nanocomposites

Designing efficient photocatalytic systems for hydrogen evolution is extremely important from the viewpoint of the energy crisis. Highly crystalline heterostructure catalysts have been established, considering their interface electric field effect and structural features, which can help improve their photocatalytic hydrogen-production activity. In this study, we fabricated a highly crystalline heterojunction consisting of ZnFe2O4 nanobricks anchored onto 2D molybdenum disulfide (MoS2) nanosheets (i.e., ZnFe2O4/MoS2) via a hydrothermal approach. The optimized ZnFe2O4/MoS2 photocatalyst, with a ZnFe2O4 content of 7.5 wt%, exhibited a high hydrogen-production rate of 142.1 mu mol h(-1)g(-1), which was 10.3 times greater than that for the pristine ZnFe2O4 under identical conditions. The photoelectrochemical results revealed that the ZnFe2O4/MoS2 heterojunction considerably diminished the recombination of electrons and holes and promoted efficient charge transfer. Subsequently, the plausible Z-scheme mechanism for photocatalytic hydrogen production under white-LED light irradiation was discussed. Additionally, the influence of cocatalysts on the photocatalytic hydrogen evolution for the ZnFe2O4/MoS2 heterostructure was investigated. This work has demonstrated a simplified coupling of one-dimensional or zero-dimensional structures with 2D nanosheets for improving the photocatalytic hydrogen production activity as well as confirmed that MoS2 is a viable substitute for precious metal-free photocatalysis. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.