High-performance electrocatalyst of activated carbon-decorated molybdenum trioxide nanocomposites for effective production of H₂ and H₂O₂

The development of high-performance electrocatalysts is crucial for efficient hydrogen (H₂) production via electrochemical water electrolysis and for hydrogen peroxide (H₂O₂) production through the oxygen reduction reaction. Herein, we present the activated carbon-decorated molybdenum trioxide (AC–MoO₃) nanocomposites, which exhibit excellent electrocatalytic performance for overall water-splitting (H₂ production) and oxygen reduction reaction (H₂O₂ production). AC–MoO₃ were synthesized using a simple hydrothermal method and displayed a large specific surface area (112 m²/g). During water electrolysis at 10 mA/cm² in 1 M KOH, AC–MoO₃ demonstrated low overpotential values of 92 and 210 mV, and showed small Tafel slope values of 52 and 78 mV/dec for the hydrogen and the oxygen evolution reactions, respectively. This led to an outstanding overall water-splitting performance, marked by a low cell voltage of approximately 1.54 V with excellent long-term stability up to 100 h under 10 mA/cm². Additionally, AC–MoO₃ achieved high mass activity (80 A/g) and approximately 80 % selectivity for H₂O₂ in the oxygen reduction reaction. The superior H₂ and H₂O₂ production activities of AC–MoO₃ can be accredited to the synergistic effects of the electrochemically active MoO₃ and the highly conductive AC. These findings suggest that AC–MoO₃ nanocomposites are highly effective for electrocatalytic H₂ and H₂O₂ production.