Fine modulating the D-band center of Co3N nanozyme for efficient oxidative degradation of emerging organic contaminants

Co 3 N nanozyme with peroxidase-like activity is synthesized via ammonia-assisted calcination of Co-based Prussian blue analogue, which displays superior catalytic activity for the oxidative degradation of organic pollutants. Co 3 N/peroxymonosulfate (PMS) system achieves complete degradation of imidacloprid (10 mg L −1 ) within 15 min under low catalyst loading (2 mg L −1 Co 3 N and 150 mg L −1 PMS), corresponding to a modified kinetic rate constant of 243.3 min −1 M −1 . Density functional theory (DFT) calculation reveals that the strong electronegativity of nitrogen reduces Co 3d electron occupancy, optimizing the Co d -band center and effectively overcoming the "oxygen wall" barrier, thereby enhancing PMS activation and promoting the formation of high-valent metal-oxo (HVMO) species, Co(IV)=O, which is the key species to achieve selective oxidation in advanced oxidation processes (AOPs). This work demonstrates that modulating the d -band center position of transition metals is a viable strategy for breaking "oxygen wall" limitation and facilitating HVMO species generation in AOPs.