Boron-Doped Co3O4/CoMoO4 heterostructure on nickel foam as a robust bifunctional catalyst for efficient overall water splitting

The development of efficient and durable bifunctional electrocatalysts is crucial for large-scale hydrogen production, yet remains challenging due to the sluggish kinetics of the oxygen and hydrogen evolution reactions. In this work, we report the rational design of a boron-doped Co 3 O 4 /CoMoO 4 heterostructure grown on nickel foam (B-Co 3 O 4 /CoMoO 4 /NF) as a robust bifunctional electrocatalyst for alkaline water splitting. By integrating B doping with Mo-induced surface reconstruction, the catalyst features abundant oxygen vacancies and optimized electronic configurations, which together accelerate reaction kinetics and improve stability. Electrochemical tests reveal that B-Co 3 O 4 /CoMoO 4 /NF requires only 299 mV to achieve 50 mA cm −2 for the OER and 255 mV to reach 50 mA cm −2 for the HER, accompanied by low Tafel slopes. The catalyst exhibits nearly unchanged activity during extended operation. In a two-electrode configuration, it delivers 50 mA cm −2 at a cell voltage of 1.741 V and maintains stable performance for 40 h, underscoring its strong potential for hydrogen production. This study provides a cost-effective and scalable strategy to construct heterostructure-doping dual-regulated catalysts with excellent bifunctional activity in renewable energy conversion.