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

Abstract

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 longterm 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.