Defect-Rich MoS2 Ultrathin Nanosheets-Coated Nitrogen-Doped ZnO Nanorod Heterostructures: An Insight into in-Situ-Generated ZnS for Enhanced Photocatalytic Hydrogen Evolution

Molybdenum disulfide has emerged as one of the promising materials, particularly as a co-catalyst for photocatalytic hydrogen evolution over the conventional and more-expensive platinum. Herein, we report novel one-dimensional/two-dimensional (1D-2D) heterostructures consisting of nitrogen-doped ZnO nanorods coated with defect-rich MoS2 nanosheets having abundant edge sulfur atoms. The optimized heterostructure consists of 15 wt % of defect-rich MoS2 nanosheets-coated on N-ZnO showed the highest H2 evolution of 17.3 mmol h–1 gcat –1 under solar light irradiation. The improved photocatalytic H2 evolution can be attributed to (i) the in-situ-generated ZnS during the process, which increased the number of interfaces, (ii) the presence of abundant exposed sulfur edge atoms in defect-rich MoS2 nanosheets, which has strong affinity for H+ ions, and (iii) the intimate heterojunction formed between N-ZnO and MoS2, which facilitates charge transfer efficiency. Hence, this work offers a promising strategy for the design and development of defect engineered heterostructure photocatalysts for greatly enhanced solar-to-fuel conversion.