Role of curvature in modulating electronic structure of active sites on hollow carbon spheres for efficient decontamination in catalytic ozonation process

The decontamination performance of heterogeneous catalytic ozonation catalysts is limited due to low electron transfer between active sites and O 3 . Herein, we modulated the electronic state of metal sites by coating copper oxides on hollow carbon (CuO x -HNC) with different spherical curvatures. CuO x -HNC with larger curvature exhibited more hydroxyl radical generation and higher degradation performance of sulfamethoxazole, achieving 60 % mineralization efficiency within 90 min. Experimental and theoretical results revealed that high curvature of hollow carbon induced a shift of π-electron density from concave to convex forming electron-rich exterior surface, which strengthened orbital overlap between Cu 3d and O 2p, consequently accelerating the electron transfer from Cu to O 3 . CuO x -HNC exhibited efficient decontamination performance for pharmaceutical wastewater in a continuous-flow reactor with COD reducing from 105 mg L −1 to below 50 mg L −1 . This study offered a valuable strategy to modify the electronic structure of catalysts for efficient wastewater decontamination.