Constructing heterojunction interface of Co3O4/TiO2 for efficiently accelerating acetaminophen degradation via photocatalytic activation of sulfite

Achieving efficient degradation of organic pollutants via activation of sulfite is meaningful but challeng-ing. Herein, we have constructed a heterogeneous catalyst system involving Co3O4 and TiO2 nanoparti-cles to form the p-n heterojunction (Co3O4/TiO2) to degrade acetaminophen (ACE) through photocatalytic activation of sulfite. Specifically, X-ray photoelectron spectroscopy analysis and theoretical calculations provide compelling evidence of electron transfer from Co3O4 to TiO2 at the heterointerface. The inter-facial electron redistribution of Co3O4/TiO2 tunes the adsorption energy of HSO3-/SO3 2- in sulfite acti-vation process for enhanced the catalytic activity. Owing to its unique heterointerface, the degradation efficiency of ACE reached 96.78% within 10 min. The predominant active radicals were identified as center dot OH, h +, and SOx center dot - through radical quenching experiments and electron spin resonance capture. Besides, the possible degradation pathway was deduced by monitoring the generated intermediate products. There-after, the enhanced roles of well-engineered compositing interface in photocatalytic activation of sulfite for complete degradation of ACE were unveiled that it can improve light absorption ability, facilitate the generation of active species, and optimize reactive pathways. Considering that sulfite is a waste from flue gas desulfurization process, the photocatalytic activation of sulfite system will open up new avenues of beneficial use of air pollutants for the removal of pharmaceutical wastewater.(c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

In this study, a heterogeneous catalyst system involving Co3O4 and TiO2 nanoparticles was constructed to degrade acetaminophen (ACE) through photocatalytic activation of sulfite. The unique heterojunction interface of Co3O4/TiO2 enabled a high degradation efficiency of ACE within 10 minutes. The roles of the engineered compositing interface were found to improve light absorption ability, facilitate the generation of active species, and optimize reactive pathways. The photocatalytic activation of sulfite system shows potential for the removal of pharmaceutical wastewater.