Surface anion-rich NiS2 hollow microspheres derived from metal-organic frameworks as a robust electrocatalyst for the hydrogen evolution reaction

Exploring highly efficient and low cost electrocatalysts for the hydrogen evolution reaction (HER) remains a significant challenge in the renewable energy area. In this study, we report a novel metal-organic framework (MOF)-engaged microwave sulfurization strategy to synthesize pyrite-structured nickel disulfide microspheres (NiS2 HMSs) with a well-defined hollow morphology and surface anion modification. The resulting NiS2 HMSs exhibit excellent performance for electrocatalyzing the HER with expected activity and durability. The optimized NiS2 HMSs need only 219 mV to offer a current density of 10 mA cm(-2) for the HER in alkaline medium, and compare favorably to previously reported Ni-based nonprecious electrocatalysts and even outperform most of the nickel sulfide-based electrocatalysts. This work will open a new avenue for the preparation of various surface anion-rich metal sulfides from the corresponding MOFs for electrocatalytic water splitting.