Cobalt and nitrogen co-doped biochar enhanced peroxymonosulfate activation for Bisphenol A degradation

The endocrine disruptor Bisphenol A (BPA) poses a potential threat to environmental ecological safety, for which a suitable treatment method needs to be found. Based on the advantages of high reactivity, chemical stability and pollutant removal efficiency of CoN co-doped material, CoN co-doped biochar (CoNC) composites with high peroxymonosulphate (PMS) activation efficiency were prepared by Co and N co-doping with fir sawdust biochar as raw material. And the activation of PMS by CoNC for the removal of BPA from environmental water has been investigated. Compared to C, NC, and CoC materials, CoNC showed improved surface roughness, more defect sites, reduced charge transfer resistance, and improved structural surface area and pore structure, with a specific surface area of 70.31 m2/g. The effects of different Co and N doping ratios, initial solution pH, and co-existing anions on the removal efficiency of BPA were also investigated. The results showed that the CoNC+PMS system exhibited excellent BPA removal compared to the original material. Under the conditions of initial solution pH 7, 0.2 g/L CoNC material, 0.3 mmol/L PMS concentration, and BPA concentration of 20 mg/L in the simulated water, the BPA removal reached 95% in 30 min. The capture experiments and electrochemical characterization showed that CoNC+PMS degraded BPA mainly through the non-radical pathway of direct charge transfer. This study provides a reference for optimising the catalytic performance of biochar and its BPA degradation in advanced oxidation technology. © 2025 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.