In-situ generation of ZnS nanoparticles in quasi-MOFs for efficient eNRR

Abstract

Inspired by the nitrogenase, transition metal sulfides have made outstanding progress in the field of eNRR. ZnS has emerged in the eNRR due to the strong photoelectric properties. Specially, the physical and chemical properties of ZnS are closely related with the support. In our study, ZIF-8-L was selected as the template to prepared ZnS/quasi-MOFs (ZnS/ZIF-8-L-T (T represents reaction temperature)) catalysts by using partial pyrolysis method. In this reaction process, the metal nodes of ZIF-8-L reacted with BDS to create ZnS nanoparticles, the organic ligands were carbonized to form the N-doped carbon support and partial framework of ZIF-8-L were remained. The hierarchical pore structure and high specific surface area of ZnS/ZIF-8-L-T not only provided a wide space for molecular diffusion, but also improved the adsorption and activation of N2. Additionally, the hydrophobicity of N-doped carbon support inhibited HER and improved FE. When the calcination temperature reached 350 °C, the obtained ZnS/ZIF-8-L-350 catalyst achieved a high NH3 yield (53.44 μg·h−1·mg−1) and a good FE (15.75%) at -0.3 V vs. RHE in 0.05 M H2SO4 solution. This work highlights the importance of support in regulating the physicochemical structure of the catalytic active center and can guide the design of advanced eNRR catalysts.