Activation of peracetic acid by cobalt hydroxide/biochar for antibiotics degradation in water

Reasonable regulation of electronic structures of heterogeneous composite catalysts can enhance the charge separation and transfer at the interface of materials, thus further promoting the catalytic performance of catalysts. Recently, peracetic acid〔CH3C(O)OOH, PAA〕 based on heterogeneous advanced oxidation process with biochar(BC) materials has attacked much interests due to various reactive oxygen species(ROS) generated in the process. In this study, biochar modified with Co(OH)2 nanoparticles(h-Co/BC) was successfully synthesized by a simple co-precipitation method, which was applied to activate PAA for tetracycline(TC) degradation. The results showed that h-Co/BC could completely degrade TC with an initial concentration of 10 µmol/L within 7 min at pH 7. The scavenger quenching tests and electron paramagnetic resonance(EPR) analysis further indicated that the produced primary ROS were alkoxy radical, which mainly including CH3COO·, CH3COOO·, ·OH and 1O2. In addition, materials characterizations combined with density functional theory calculation showed that biochar was successfully modified with Co(OH)2 nanoparticles. Thus, the Co 3d-band in h-Co/BC was closer to Fermi level compared with that in pure Co(OH)2, benefiting to directional electron transfer, which could then be easily captured by PAA for cleavage to ROS. This study provided a new method for synthesis of functional materials applied in PAA-based AOPs.