Titanium dioxide induced nickel-iron alloy-based precatalyst towards efficient and durable oxygen evolution reaction

Highly active and stable electrocatalysts are essential to facilitate the oxygen evolution reaction (OER) during alkaline water splitting. Herein, a titanium dioxide supported NiFe-based OER electrocatalyst (NiFe/TiO2) was developed through simple impregnation reduction method. The introduction of TiO2 support not only enhances the catalyst stability, but also induces the formation of NiFe alloy pre-catalyst layer on the oxide surface. In situ Raman revealed that the NiFe alloy was partially transformed into highly active NiOOH species in OER process. In situ infrared and theoretical calculations confirm the promoted formation of *OOH intermediate on NiFe/TiO2 surface and thus accelerates the OER. The NiFe/TiO2 catalyst achieves excellent OER activity delivering 10 mA cm−2 at low overpotential of 240 mV in 1.0 M KOH. The anion exchange membrane water electrolyzer with NiFe/TiO2 achieves 500 mA cm−2 with cell voltage of 1.72 V, and good stability is maintained for 300 h. This study advances the effort of developing efficient and durable alkaline OER catalysts. [Display omitted] •Titanium dioxide supported NiFe alloy OER catalyst is prepared.•The NiFe/TiO2 exhibits excellent OER activity and stability in 1.0 M KOH.•Dynamical evolution of NiFe/TiO2 was studied by in situ Raman and ATR-FTIR analysis.•AEMWE has a cell voltage of 1.72 V at 500 mA cm−2 and long-term stability.•OER mechanism of NiFe/TiO2 was researched by DFT calculations.