Visible-light-driven removal of 4-tert-butylphenol by coupled photoredox and enzyme catalysis

The combination of photocatalysis and enzyme catalysis makes many previously difficult or slow chemical reactions easy to realize. A novel laccase@g−C3N4 biohybrid catalyst was successfully synthesized using a simple in situ synthesis method to remove 4-tert-butylphenol (4-t-BP). A series of characterization methods were used to investigate the structure, morphology, chemistry, and optical properties of biohybrid catalysts. Laccase@g−C3N4 has improved photogenerated electron-hole pair separation efficiency and charge carrier mobility, as well as photocatalytic activity, with a removal rate of 4-t-BP nearly 100% within 180 min. The catalyst recycling test revealed that the composite could maintain its high removal efficiency after 10 recyclings. Meanwhile, the photocatalytic mechanism investigation reveals that ∙O2− play critical roles in the removal of 4-t-BP by g−C3N4. A detailed examination of the mechanism and pathway of 4-t-BP removal by photoenzyme oxidation was also carried out. This biohybrid catalyst opened up a new avenue for the advancement of environmental protection technology. •Laccase@g−C3N4 photoenzymatic catalyst was synthesized by a simple in situ synthesis method.•Extraction of eCB- from g−C3N4 by laccase triggered the synergistic interaction between laccase and g−C3N4.•Photoenzymatic oxidation of 4-t-BP is a surface-controlled process.•Both the g−C3N4 and laccase generated free radicals couple to form oligomers and polymers.•Lac@g−C3N4 displayed excellent catalytic activity, stability and reusability.