Facile synthesis of CoMoO₄/CoMoB/boron-doped carbon nanocomposite as a highly durable bifunctional electrocatalyst for overall water splitting

Structural modulation of earth-abundant metal-based materials is essential for sustainable renewable energy technology progress. Herein, we report a simple solvothermal synthesis of boron-(B)-doped carbon-based CoMoO₄/CoMoB (CoMo@BC) nanocomposite to serve as a bi-functional electrocatalyst for overall water splitting. The resulting CoMo@BC catalyst achieved 10 mA cm⁻² of current density at low overpotential of 167 and 279 mV for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, in 1.0 M KOH with robust stability over 100 h. The CoMo@BC sample serves as a cathode, and the anode requires 1.650 V to attain 10 mA cm⁻² of current density in 1.0 M KOH for overall water splitting. Results reveal that incorporating boron into the carbon matrix demonstrates a high degree of modulation of their electronic structure, resulting in improved electric-conductivity and the construction of abundant electrochemical active-sites. This study presents a well-arranged nanoarchitecture and a simple fabrication strategy for efficient water-splitting electrocatalysts.