Fenton-like photocatalysts derived from walnut shell exhibit rapid pollutant degradation with high H2O2 utilization efficiency under neutral conditions

As time progresses and pollutants become more diverse, catalysts with a broad range of applicability are gaining increased attention. This paper proposes a Fenton-like photocatalyst derived from walnut shell powder for the rapid degradation of various pollutants and the efficient utilization of hydrogen peroxide under neutral conditions. The walnut shell biomass carbon-loaded iron catalyst (WSF 0.5) was obtained by ball-milling and lowtemperature calcination of walnut shell powder and ferric chloride hexahydrate. Notably, WSF 0.5 achieved essentially 100 % phenol removal within 7 min (kobs = 0.62 min-1) and maintained strong catalytic activity over a wide pH range. Under neutral conditions, H2O2 utilization reached 51 % within 30 min at WSF 0.5 concentration of 0.2 g/L. FFA probe experiments and quenching results confirmed that the main active species was center dot OH, while no 1O2 was present in the system. Structural analysis, XPS analysis, and cycling experiments confirmed the excellent cycling stability of WSF 0.5. Additionally, WSF 0.5 demonstrated a strong degradation effect on various pollutants, including dyes (e.g., methylene blue), pesticides (e.g., 2-mercaptobenzothiazole), and antibiotics (e. g., oxytetracycline). These results indicate that WSF 0.5 not only exhibits high catalytic performance but also promotes environmentally friendly degradation.