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 MoNxOy nanozyme for highly efficient degradation of phenolic pollutants at high temperature. Both the laccase-like and peroxidase-like activities of MoNxOy 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 MoNxOy + H₂O₂ is 97.0 ± 0.2% at 60 °C within 20 min. Moreover, MoNxOy 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.