Doping vacancy synergy engineering: Ce-doped FeNi-Sx micro-succulent ameliorating electrocatalytic oxygen evolution performance

The co-control strategy of doping and vacancy has proved to be an effective and flexible approach in the development of efficient catalysts because of the synergistic regulation of electronic structure and active site number. Here, we synthesized an electrocatalyst with a special micromorphology of succulent plants. In addition, the doping of the rare earth element Ce with a large ionic radius in NiFe bimetallic sulfides is accompanied by a large number of vacancies. Ion doping synergistic with vacancy engineering improves the electrochemical intrinsic performance in the OER process and has enhanced electron transfer ability and electrochemical specific surface area, thus exhibiting high electrocatalytic OER performance, small Tafel slopes, ultralow overpotential of 294 mV at 100 mA cm−2 and 276 mV at 50 mA cm−2 and robust operating durability. Combined with DFT calculations, the role of Ce ions in the NiFe bimetallic sulfide system was revealed. This work not only provides a strategy for designing ion doping to enhance vacancy concentration but also constructs an efficient and stable oxygen evolution electrocatalyst system, which provides an alternative path for designing efficient electric and photocatalysts.