Fig. 5: Influence of substitution process on OER mechanism.

a, b In-situ FT-IR spectra of (NiCo)S_0.89 and (NiCo)S_1.33 were recorded during the multi-potential steps. c Signal strength variation diagram of characteristic FT-IR peaks of OOH_ads, M-O^* and OH_ads. d The ratio of the LOM pathway extracted from DEMS signals of ³⁴O₂ and ³²O₂ of (NiCo)S_0.89 and (NiCo)S_1.33 from the reaction products cycled in H₂¹⁶O aqueous KOH electrolyte. e Schematic diagram of the lattice oxygen mechanism with lattice sulfur-oxygen substitution process.