S-doped nickel-iron hydroxides synthesized by room-temperature electrochemical activation for efficient oxygen evolution

Abstract Anion doping shows promising potential in optimizing the adsorption and desorption of reaction intermediates on the surface of NiFe-based layered double hydroxide (NiFe-LDH) for oxygen evolution reaction (OER). However, conventional doping methods are meticulous and complex. Hence, S-doped NiFe-LDH (S-NiFe-LDH-t-A) driven by short-time room-temperature electrochemical activation procedure is synthesized. The NiFe-LDH prefabricated by spontaneous substrate corrosion ensures large active surface area, exposed active sites and long-term robustness. Then moderate S doping electrochemically motivated is applied to the regulation of NiFe-LDH, which not only improves the bonding between metals and reaction intermediates but also induces decreased free energy, thus enhancing OER performance. Electrochemical measurements verified the low overpotential of 270 mV at 50 mA cm-2 and favorable durability for optimized S-NiFe-LDH-9-A benefited from the synergistic effect between NiFe-LDH and S species. This work provides a facile electrochemical activation strategy for anion doping, which show implications for the design of advanced catalysts.