Contact electrocatalysis-based synthesis of multimetal catalysts for the electrocatalytic oxygen evolution reaction

Hydrogen energy has garnered considerable attention as a clean and sustainable alternative to fossil fuels in the global pursuit of carbon neutrality. Cost-effective hydrogen production requires the development of efficient and scalable water-splitting catalysts. In this regard, herein, we use ultrasonically driven contact electrocatalysis method to synthesize multimetal hydroxide catalysts for the oxygen evolution reaction (OER). This synthesis approach, performed under mild conditions, utilizes carbon paper, nickel foam, or copper foam as the substrate in metal salt solutions, achieving rapid catalyst formation (within 30 s). Among catalysts containing combinations of >10 metals formed by this process, iron-cobalt oxyhydroxide (FeCoOOH) exhibits notable OER performance in 1.0 M KOH. FeCoOOH achieves an overpotential of 351 mV at a current density of 100 mA cm^-2 with a Tafel slope of 40.2 mV dec^-1 on carbon paper, maintaining stability over 50 h of continuous operation. Comparative experiments demonstrate that ultrasonic treatment is crucial for the low-cost and scalable production of high-efficiency catalysts. Overall, this synthesis of advanced OER catalysts can benefit large-scale hydrogen production technologies.