Thermophilic MoNxOy nanozyme for highly efficient degradation of phenolic pollutants

In industry phenolic wastewaters are generated at high temperature and required for cooling before post-treatment. The utilization of thermal energy for the treatment of phenolic wastewaters is often overlooked. Herein, we utilize thermophilic MoN_xO_y nanozyme for highly efficient degradation of phenolic pollutants at high temperature. Both the laccase-like and peroxidase-like activities of MoN_xO_y nanozyme increase with the temperature up to 90 °C. The efficiency of phenol oxidation at 60 °C is about 3-fold of that at 25 °C. Phenol is mineralized into CO₂ and H₂O, the removal of total organic carbon by MoN_xO_y + H₂O₂ is 97.0 ± 0.2% at 60 °C within 20 min. Moreover, MoN_xO_y nanozyme can also degrade other phenolic pollutants such as 2,4-dichlorophenol, pyrocatechol, 4-aminophenol and o-nitrophenol. The catalytic mechanism and phenol degradation route are also analyzed. This work provides a promising strategy for highly efficient treatment of phenolic wastewaters in an energy-saving way.