Kill two birds with one stone: simultaneous removal of volatile organic compounds and ozone secondary pollution by a novel photocatalytic process

Abstract

Volatile organic compounds (VOCs) originating from diverse sources with complex compositions pose threats to both environmental safety and human health. Photocatalytic treatment of VOCs has garnered attention due to its high efficacy at room temperature. However, the intricate photochemical reaction generates ozone (O₃), causing secondary pollution. Herein, our work developed a novel “synergistic effect” system for photocatalytic co-treatment of VOCs and O₃ secondary pollution. Under the optimized reactor conditions simulated with computational fluid dynamics (CFD), MgO-loaded g-C₃N₄ composites (MgO/g-C₃N₄) were synthesized as efficient catalysts for the photocatalytic synergistic treatment process. Density functional theory (DFT) calculations, characterization, and electron paramagnetic resonance (EPR) tests revealed that the addition of MgO reduced the band gap of g-C₃N₄, and increased O₃ molecule adsorption in the composites, efficiently harnessing the synergistic effect of O₃ to generate a significant quantity of reactive oxygen radicals, thereby facilitating the removal of VOCs and O₃. This study provides new insights for simultaneous elimination of VOCs and O₃ secondary pollution by a photocatalytic process.