Enhanced Removal of Phenols by MIZ-Cu Nanozyme Exhibiting Laccase-like Activity and Broader Adaptability to Temperature and pH Conditions

Phenolic compounds, classified as persistent organic pollutants, pose a significant threat to both human health and environmental safety. Therefore, the efficient removal of phenolic substances from water is of paramount importance. Laccase, a multicopper oxidase, is commonly utilized for the efficient removal of phenolic contaminants from water due to its highly effective catalytic activity towards phenolic compounds. However, natural laccase exhibits certain limitations that impede its practical implementation in industrial settings, including a restricted pH activity range, diminished enzymatic efficacy at elevated temperatures, and substantial cost implications. In this work, we prepared a nanozyme (MIZ-Cu, MIZ: 2-methylimidazole) with laccase-like activity by coordinating 2-methylimidazole and copper. This nanozyme overcomes the deactivation issues observed in natural laccase under high temperature and alkaline conditions. The catalytic activity of the MIZ-Cu towards phenolic compounds surpasses that of natural laccase across a wide range of temperature and pH conditions. Under pH=9, 80 degrees C, and 500 mmol/L NaCl conditions, the removal rate of four phenols (catechol, hydroquinone, resorcinol, and phloroglucinol) by MIZ-Cu was much higher than that of natural laccase. The results also demonstrate exceptional removal rates in natural aquatic environments, thereby presenting a promising approach for the treatment of phenol-containing wastewater originating from industrial facilities.

Automated summary

Phenolic compounds are significant pollutants that pose a threat to human health and the environment. A nanozyme (MIZ-Cu) with laccase-like activity was developed to efficiently remove phenolic contaminants from water, overcoming the limitations of natural laccase. The MIZ-Cu showed superior catalytic activity compared to natural laccase across a wide range of temperature and pH conditions, making it a promising approach for industrial wastewater treatment.