Anion–cation dual-doping-induced electronic structure modulation of NiMoO4 nanorods for boosting oxygen evolution reaction

Developing an efficient non-noble metal catalyst to accelerate the oxygen evolution reaction (OER) is essential for enabling the widespread use of electrochemical water splitting. In this work, we proposed a strategy of anion–cation dual doping to fabricate Fe and S dual-doping NiMoO 4 one-dimensional nanorods on nickel foam (Fe-NiMoO 4 -S/NF) through a simple preparation method. The combination of experimental results and theoretical calculations demonstrates that the simultaneous incorporation of both Fe and S can effectively regulate morphology and electronic structure, enhance charge transfer, increase the exposure of active sites, and optimize the adsorption of OER intermediates. The optimized Fe-NiMoO 4 -S/NF reveals excellent OER activity and structure stability, achieving a low overpotentials of 255 mV at 50 mA cm⁻ 2 in alkaline solution (1.0 M KOH) and 292 mV at 50 mA cm⁻ 2 in simulated alkaline seawater (1.0 M KOH + 0.5 M NaCl). Furthermore, the Fe-NiMoO 4 -S/NF maintains robust stability at high current density for 100 h and has small Tafel slopes of 66.0 and 78.1 mV dec⁻ 1 in alkaline solution and simulated alkaline seawater, respectively. In addition, overall water splitting at 10 mA cm⁻ 2 is achieved with an exceptionally low cell voltage of 1.54 V using the Fe-NiMoO 4 -S || Pt/C configuration. Thus, this study provides a significant guideline for the development of non-noble metal OER electrocatalysts through anion–cation dual-doping strategy. Graphical abstract A novel Fe and S dual-doped NiMoO4 one-dimensional nanorods on nickel foam (Fe-NiMoO4-S/NF) were designed for boosting the oxygen evolution reaction activity.