Abstract:Using hydrothermal method, adjust n(Co)∶n(Ni) in the precursor, load two kinds of bimetallic sulfides (NiCo2S4 and Ni2CoS4), and preparation of oxygen evolution catalysts NiCo2S4/NF and Ni2CoS4/NF.Based on SEM,XRD andXPS characterization, and electrochemical performance testing were conducted to investigate the effects of n(Co)∶n(Ni) (1:2~3:2) on the structural morphology, elemental composition, and oxygen evolution performance of the catalyst.When n(Co)∶n(Ni)=1:2, the obtained metal sulfide is cubic phase Ni2CoS4; When n(Co)∶n(Ni)≥1, the obtained metal sulfide is cubic phase NiCo2S4. When n(Co)∶n(Ni)=1:1, the prepared NiCo2S4/NF exhibits superior OER performance. Compared to Ni2CoS4/NF, when the current density is 20 mA/cm2, its overpotential is only 216 mV, The Tafel slope is 72 mV/dec, which has a larger electrochemical active area and lower charge transfer resistance. During the OER process, MOOH (M=Co,Ni) forms on the surface of the catalyst is conducive to the progress of OER; According to density functional theory (DFT) calculations, The Gibbs free energy required for OER in NiCo2S4 is lower.