High specific surface area graphene-like biochar for green microbial electrosynthesis of hydrogen peroxide and...

Green electrosynthesis of hydrogen peroxide (H₂O₂) is a research hotspot in environmental chemistry, particularly for wastewater and sanitation applications, with microbial fuel cells (MFCs) offering a self-sustaining route for in situ production. This investigation showcases the application of chemically activated bagasse biochar (AcBC), a graphene-like carbon material, as a cathode catalyst in a ceramic membrane-fitted MFC for H₂O₂ generation and bisphenol A (BPA) degradation. The AcBC had an exceptionally high specific surface area of 1604 m²/g and mimicked the physicochemical characteristic of graphene. The MFC having the AcBC-catalysed cathode attained a maximum H₂O₂ yield of 248. 9 ± 12.5 mg/L (retention time of 12 h) and peak power density of 125.62 ± 5.62 mW/m². Moreover, this system was tailored into a bioelectro-Fenton system by doping Zn-Fe over AcBC (Zn-Fe/AcBC) that instigated hydroxyl radical formation, thus responsible for removing 95.46 ± 3.50 % of Bisphenol A (BPA, initial concentration = 10 mg/L) in 300 min. Total organic carbon (initial concentration = 47.1 ± 2.3 mg/L) of BPA-containing real wastewater was reduced by 51.4 ± 3.6 % in 300 min while consistently achieving >90 % removal of BPA over eight continuous cycles. Thus, this research demonstrates the potential of biomass-derived graphene-like carbon in catalyzing green H₂O₂ synthesis for removal of biorefractory organics while achieving sustainable wastewater treatment.