High efficiency heterogeneous Fenton-like catalyst biochar modified CuFeO2 for the degradation of tetracycline: Economical synthesis, catalytic performance and mechanism

The heterogeneous Fenton-like catalysts biochar modified CuFeO2 (CuFeO2/BC) were fabricated by hydrothermal method without additional chemical reducing agent. The systematic characterization demonstrated that higher CuFeO2 particles dispersion and larger BET surface area of CuFeO2/BC catalyst contributed to higher catalytic activity towards the tetracycline (TC) degradation compared to pure-phase CuFeO2. The optimum conditions for TC removal were 598.63 mg L-1 of CuFeO2/BC-1.0, 57.63 mM of H2O2 and pH = 6.27 according to the result of a response surface methodology based on the central composite design. The CuFeO2/BC-1.0 exhibited an excellent reusability and good stability by recycling degradation. The OH was evidenced to the main active radical by scavenging experiments and electron spin resonance. The XPS revealed that the high catalytic efficiency was attributed to the synergistic effect of Fe3+/Fe2+ and Cu2+/Cu+ redox cycles, and the degradation intermediates of TC and toxicity analysis were evaluated.