Confined construction of COF@Cu-nanozyme with high activity and stability as laccase biomimetic catalyst for the efficient degradation of phenolic pollutants

Construction of highly-active nanozymes featuring merits of enzymes and nanomaterials is challenging for biomimetic catalysis. Herein, "confined coordination " strategy was proposed to engineer a novel laccasenanozyme supported on mesoporous COF-OMe (Cu-Cys@COF-OMe) for the effective degradation of phenolic pollutants. In-situ L-Cysteine modification and confined Cu-coordination implanted unique Cys-multicopper (Cu+/Cu2+) cluster in COF-OMe mesopores, and engineered biomimetic active pockets to which achieved efficient synergistic diffusion-adsorption-catalysis. Cu-Cys@COF-OMe realized 1.9 times higher enzymatic activity than that of laccase and 2.1-17.0 times higher monatomic copper activity than that of reported state-of-the-art laccase nanozymes, respectively. Besides, Cu-Cys@COF-OMe displayed catalytic merits of nano-materials over laccase, which demonstrated enhanced catalytic activity with temperature and excellent stability under variable reaction conditions. Cu-Cys@COF-OMe nanozyme exhibited 1.4 times faster degradation kinetics (of laccase) for phenolic pollutants, which was further intensified (3.4 times) after exposure to NaCl. This work opens a promising avenue for better design of laccase nanozymes to realize effective phenolic pollutants degradation for large-scale applications.