Synergistically improving permeability and catalytic efficiency of catalytic membrane for gravity-driven antibiotic degradation

Abstract

Catalytic membrane with physical size sieving and peroxymonosulfate-induced catalytic oxidation is appealing for wastewater remediation. However, restricted by the retention time of the contaminant in membrane, exceptional degradation efficiency is usually achieved at lower permeation conditions. Herein, to improve the permeance while maintaining high degradation efficiency, heterogeneous Cu doping was employed to tune the electronic structure of LaCoO3 perovskite, and the catalytic activity was further optimized by modulating Cu: Co ratios. Besides, Cu-doped LaCoO3 was anchored in a SiO2 fiber membrane with decent connectivity. Benefiting from the enriched local concentration of the reactants and highly connected fiber structures, attractive catalytic efficiency and permeability can be achieved simultaneously. About 99% of tetracycline hydrochloride (TC) was degraded within 12 min with a k constant of 0.4765 min−1, and the flux reached up to 2575.4 L/m2h under gravity, which was 10–70 times higher than other reported catalytic membranes. Density functional theory proved the enhanced interaction between PMS and catalytic membrane, and mechanism analysis demonstrated that singlet oxygen and sulfate radicals dominated the TC degradation process. Furthermore, the catalytic membrane also possessed favorable stability and regeneration capacities. This work highlights a promising strategy for fabricating high-efficient catalytic membranes, which can improve wastewater remediation efficiency.