Co2O3 functionalized SiC membrane for dye removal: Sintering necks enable dual-functionality in low-temperature sintering and catalytic ozonation

Densification of silicon carbide (SiC) ceramic membrane typically requires sintering temperatures above 2000 °C, resulting in high energy consumption and substantial fabrication costs, and conventional SiC membrane exhibit limited removal efficiency for small molecules. To address these challenges, a co-sintering method was employed to fabricate cobaltic oxide (Co 2 O 3 ) loaded SiC catalytic membrane, with the Co 2 O 3 content systematically optimized. Co 2 O 3 functions as both a sintering temperature-lowering aid and an active site for catalytic ozonation of pollutants. Compared to pure SiC membrane (water permeability: 1200 L m −2  h −1 bar −1 ; flexural strength: 10.5 MPa), the Co@SiC membrane demonstrated significant improvements in both water permeability (1400 L m −2  h −1 bar −1 ) and mechanical strength (13.0 MPa). Numerical simulation further elucidated the neck formation dynamics. Moreover, Co@SiC membrane effectively degrades 95 % Congo red within 20 min, attributed to the generation of superoxide radicals (•O 2 − ). Density functional theory (DFT) calculations illustrated Co sites can effectively absorb ozone molecules and break O-O bond in ozone to generate •O 2 − . Fukui index analysis further indicated •O 2 − tend to attack N=N double bonds in dye molecules. This study proposes a comprehensive understanding of low-temperature sintering behavior and catalytic ozonation performance of Co 2 O 3 modified composite membrane, offering a sustainable strategy for membrane fabrication and wastewater treatment.