Enhanced photocatalysis by defect-engineered CeO2 with sulfite activation under visible light irradiation

Abstract

Sulfite-based advanced oxidation processes (s-AOP) have recently garnered significant attention due to their ability to generate highly oxidative sulfate radicals and eliminate contaminants from water. A state-of-the-art platform has been developed through the synergistic combination of s-AOP and photocatalysis under visible light as weak as ambient indoor daylight. This platform achieved an enhanced degradation efficiency for defect-engineered CeO2 nanocubes by using sodium sulfite instead of SO2, resulting in a synergy factor of up to 88%. The reaction pathways, intermediates, ion leaching and the possible influence of aqueous conditions during the methyl orange degradation have been investigated. The CeO2/Na2SO3/vis-light platform exhibits promising prospect as a system to enhance conventional s-AOP in wastewater treatment or disinfection. It demonstrates excellent performance in terms of pH sensitivity, anion influence, and resistance to leaching. This highlights its significant potential for practical applications and future process scale-up.