An efficient NiS@N/S-C hybrid oxygen evolution electrocatalyst derived from metal-organic framework

Exploring earth-abundant oxygen evolution electrocatalysts is a challenge for cost-effective production of hydrogen from water splitting and fuel cells. Herein, the NiS@N/S-C nanocomposites composed of NiS particles embedded in N/S co-doped carbon substrate were synthesized by carbonization of metal-organic framework (MOF) of the Ni (II) complex with vanillic thiosemicarbazone. The MOF-derived NiS@N/S-C hybrids exhibited excellent electrochemical performance for oxygen evolution reaction (OER) in alkaline solution, yielding a low onset potential of 1.54 V (vs. the reversible hydrogen electrode), and the potential only changed 10 mV after chronopotentionmetric response at 10 mA cm−2 for 10 h. The resulted high OER activity and strong stability of hybrids was derived from the active NiS nanostructure characteristic and the well-dispersed NiS nanoparticles encapsulated in carbon substrate formed in situ, the strong interaction between NiS particles and substrate species, as well as co-doping effect of N/S atoms on substrates. Our work gave a new method to prepare catalysts and demonstrated that NiS@N/S-C nanocomposite was a promising non-precious catalyst for water splitting.