Cu/Fe co-modified nitrogen self-doped biochar as a heterogeneous Fenton-like catalyst for degradation of organic pollutants: Synthesis, performance, and mechanistic study

Abstract

In this work, Cu/Fe modified nitrogen self-doped cyanobacterial biochar was synthesized for the first time as a heterogeneous Fenton-like catalyst to study its catalytic degradation ability of Methylene Blue (MB) organic dye. The prepared samples were characterized by SEM, BET, XRD, and so on. The effects of pyrolysis temperature, acid treatment, heat radiation source, H2O2 concentration, initial pH, and catalyst dosage on the degradation of MB were systematically investigated. The results showed that the catalytic degradation of MB by CuFeXBC400 catalyst was as high as 99.78% within 30 min under the optimum conditions. The catalytic degradation mechanism was derived based on quenching experiments and LC-MS. Cyanobacteria not only provided a carbon source as a biochar skeleton loaded with bimetals but also provided N source to promote Fe2+ and Fe3+ cycling in the Fenton reaction. In addition to its high catalytic activity, the catalyst can still reach 90% MB removal after five runs and calcination regeneration, which has good application prospects in the removal of organic pollutants from water.