Preparation of functionalized porous chitin carbon to enhance the H2O2 production and Fe3+ reduction properties of Electro-Fenton cathodes for efficient degradation of RhB

The performance of Electro-Fenton (EF) cathode materials is primarily assessed by H2O2 yield and Fe3+ reduction efficiency. This study explores the impact of pore structure in chitin-based porous carbon on EF cathode effectiveness. We fabricated mesoporous carbon (CPC-700-2) and microporous carbon (ZPC-700-3) using template and activation methods, retaining nitrogen from the precursors. CPC-700-2, with mesopores (3-5 nm), enhanced O2 diffusion and oxygen reduction, producing up to 778 mg/L of H2O2 in 90 min. ZPC-700-3, with a specific surface area of 1059.83 m2/g, facilitated electron transport and ion diffusion, achieving a Fe2+/Fe3+ conversion rate of 79.9%. EF systems employing CPC-700-2 or ZPC-700-3 as the cathode exhibited superior degradation performance, achieving 99% degradation of Rhodamine B, efficient degradation, and noticeable decolorization. This study provides a reference for the preparation of functionalized carbon cathode materials for efficient H2O2 production and effective Fe3+ reduction in EF systems.

Heterogeneous electro-Fenton treatment of chemotherapeutic drug busulfan using magnetic nanocomposites as catalyst

The rapid and efficient mineralization of the chemotherapeutic drug busulfan (BSF) as the target pollutant has been investigated for the first time by three different heterogeneous EF systems that were constructed to ensure the continuous electro-generation of H2O2 and •OH consisting of: i) a multifunctional carbon felt (CF) based cathode composed of reduced graphene oxide (rGO), iron oxide nanoparticles and carbon black (CB) (rGO-Fe3O4/CB@CF), ii) rGO modified cathode (rGO/CB@CF) and rGO supported Fe3O4 (rGO-Fe3O4) catalyst and iii) rGO modified cathode (rGO/CB@CF) and multi walled carbon nanotube supported Fe3O4 (MWCNT-Fe3O4) catalyst. The effects of main variables, including the catalyst amount, applied current and initial pH were investigated. Based on the results, H2O2 was produced by oxygen reduction reaction (ORR) on the liquid-solid interface of both fabricated cathodes. •OH was generated by the reaction of H2O2 with the active site of ≡FeII on the surface of the multifunctional cathode and heterogeneous EF catalysts. Utilizing carbon materials with high conductivity, the redox cycling between ≡FeII and ≡FeIII was effectively facilitated and therefore promoted the performance of the process. The results demonstrated almost complete mineralization of BSF through the heterogeneous systems over a wide applicable pH range. According to the reusability and stability tests, multifunctional cathode exhibited outstanding performance after five consecutive cycles which is promising for the efficient mineralization of refractory organic pollutants. Moreover, intermediates products of BSF oxidation were identified and a plausible oxidation pathway was proposed. Therefore, this study demonstrates efficient and stable cathodes and catalysts for the efficient treatment of an anticancer active substance.