Using battery waste-derived Mn2O3 incorporated into sugarcane biomass-based activated carbon gas diffusion electrodes for sustainable and efficient H2O2 electrogeneration

Abstract

In this study, gas diffusion electrodes (GDEs) supported on sustainable sugarcane bagasse-derived carbon (Cscb) and modified with different amounts of Mn2O3 nanoparticles derived from battery waste were used for H2O2 electrogeneration via the two-electron oxygen reduction reaction mechanism (2e− -ORR). A thorough physicochemical analysis of the Cscb- Mn2O3 materials showed well-dispersed Mn2O3 nanocrystals, with predominantly α-Mn2O3 bixbyite cubic phases, and a conductive carbonaceous structure. Electrochemical tests in neutral media revealed that the presence of Mn2O3 favored the two-electron oxygen reduction pathway, leading to roughly 89.26% improvement in selectivity toward H2O2. This enhancement in selectivity was accompanied by a reduction in the average number of electrons transferred, approaching the theoretical value of ∼2, which is intrinsically required for efficient peroxide generation via the 2e− -ORR. The incorporation of Mn2O3 into Cscb significantly improved the overall electrochemical performance of the material; at 40 mA cm−2, H2O2 production increased by 79 mg L−1 while energy consumption decreased by 22 kWh kg−1 H2O2. This study demonstrates that the proposed GDE/Cscb-Mn2O3 combine the sustainability of biomass-derived carbon with the catalytic efficiency of metal oxide, resulting in high H2O2 yields, lower energy demand, and favorable interfacial properties. These findings highlight the potential of Cscb- Mn2O3 as a low-cost, environmentally friendly, and efficient platform for decentralized H2O2 production, contributing to green electrochemical technologies and advanced oxidation processes.