Aluminum incorporation engineering in CoMoO4 nanorods: Tailoring electrocatalytic architectures for superior oxygen evolution reaction

CoMoO₄ is a promising oxygen evolution reaction (OER) catalyst owing to its distinct crystallographic configuration and redox versatility. However, its practical applications remain limited by its suboptimal active site density and inefficient charge-transport mechanisms. To address these challenges, a one-step hydrothermal method is developed to introduce Al atoms into the CoMoO₄ framework, yielding an Al-doped electrocatalyst (Al–CoMoO₄-1/NF) featuring enhanced functionality. Al–CoMoO₄-1/NF achieves an OER current density of 10 mA cm⁻² at an overpotential of 184 mV, demonstrating a Tafel slope of 55.6 mV dec⁻¹. In full water-splitting configurations, the Al–CoMoO₄-1/NF(+)||Pt/C/NF(−) electrolyzer attains 10 mA cm⁻² at 1.52 V, outperforming various nonprecious-metal-based systems. Al integration regulates ∗OH intermediate adsorption equilibrium and strengthens interactions with oxygenated species. Al incorporation considerably reduces charge-transfer resistance and accelerates reaction kinetics. The larger specific surface area of the Al-doped structure exposes more active sites and increases the electrode/electrolyte interfacial contact area, improving catalytic activity. These synergistic effects enhance intrinsic activity and mass-transport efficiency. Leveraging abundant Al for structural modulation, this study advances the rational design of high-performance, cost-efficient OER catalysts for sustainable energy conversion.