Singlet oxygen triggered by carbon doped boron nitride nanosheets for enhanced removal of tetracycline by peroxymonosulfate activation

The catalytic performance of non-radical based AOP (advanced oxidation processes) is less susceptible to the inorganic anions and natural organic matters (NOMs), thus non-radical based AOP is widely used in complex aqueous matrices. However, the activity of catalysts mediating the non-radical pathway is limited. Herein, a catalyst based on non-radical pathway with excellent catalytic activity was designed. Pyrolysis in one step was used to prepare carbon doped hexagonal boron (C-BN) catalyst, this catalyst showed excellent degradation performance in activating peroxymonosulfate (PMS) for tetracycline (TC) degradation. After doping C, the removal rate of TC (10 mg/L) could reach over 99% within 25 min, which was three times that of h-BN. Surface area, hydrophilicity, and electron transport rate all contributed to the improvement of catalytic performance. Combined with experimental and DFT (density functional theory) analysis, 1O2 and electron transfer mechanisms played a significant role in the degradation of TC in the 40% C-BN system. Because of that, the catalyst maintained excellent catalytic activity under different pH, different pollutants, different anions, and other environmental factors, showing its good resistance. This study could enrich the degradation mechanism of non-radical based AOP in the C-BN catalysts.