{"title":"Photocatalyst deactivation in gaseous VOCs photooxidation: Mechanisms, stability enhancement, and regeneration strategies","authors":"Asad Mahmood","doi":"10.1016/j.jece.2025.117569","DOIUrl":null,"url":null,"abstract":"<div><div>Air pollution from volatile organic compounds (VOCs) has raised interest in photocatalytic oxidation for air cleaning. However, photocatalysts often lose activity under real conditions. Unlike laboratory settings, real air contains many organic compounds. These can cause competitive adsorption, form reactive byproducts, and poison the surface. As a result, photocatalytic performance drops over time. This review explains the main reasons for deactivation in gas-phase systems. These include the buildup of carbon residues, formation of byproducts with nitrogen or sulfur, coke deposits, and damage to the material’s structure. We also discuss how surface defects, crystal structure, and particle shape affect both activity and durability. Different methods to restore activity are reviewed. These include heating, chemical cleaning, and light-based recovery. We also highlight recent advances in material design. Examples include single-site catalysts and porous structures such as metal organic frameworks. These materials can improve selectivity and resist deactivation. Machine learning is also gaining attention. It can help predict stability and guide the design of better photocatalysts. Although deactivation is widely studied, few reports focus on gas-phase systems with a clear mechanistic view. This review fills that gap. It combines experiments with analysis to support the design of stable and reusable photocatalysts for clean air.</div></div>","PeriodicalId":15759,"journal":{"name":"Journal of Environmental Chemical Engineering","volume":"13 5","pages":"Article 117569"},"PeriodicalIF":7.4000,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Environmental Chemical Engineering","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2213343725022651","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Air pollution from volatile organic compounds (VOCs) has raised interest in photocatalytic oxidation for air cleaning. However, photocatalysts often lose activity under real conditions. Unlike laboratory settings, real air contains many organic compounds. These can cause competitive adsorption, form reactive byproducts, and poison the surface. As a result, photocatalytic performance drops over time. This review explains the main reasons for deactivation in gas-phase systems. These include the buildup of carbon residues, formation of byproducts with nitrogen or sulfur, coke deposits, and damage to the material’s structure. We also discuss how surface defects, crystal structure, and particle shape affect both activity and durability. Different methods to restore activity are reviewed. These include heating, chemical cleaning, and light-based recovery. We also highlight recent advances in material design. Examples include single-site catalysts and porous structures such as metal organic frameworks. These materials can improve selectivity and resist deactivation. Machine learning is also gaining attention. It can help predict stability and guide the design of better photocatalysts. Although deactivation is widely studied, few reports focus on gas-phase systems with a clear mechanistic view. This review fills that gap. It combines experiments with analysis to support the design of stable and reusable photocatalysts for clean air.
期刊介绍:
The Journal of Environmental Chemical Engineering (JECE) serves as a platform for the dissemination of original and innovative research focusing on the advancement of environmentally-friendly, sustainable technologies. JECE emphasizes the transition towards a carbon-neutral circular economy and a self-sufficient bio-based economy. Topics covered include soil, water, wastewater, and air decontamination; pollution monitoring, prevention, and control; advanced analytics, sensors, impact and risk assessment methodologies in environmental chemical engineering; resource recovery (water, nutrients, materials, energy); industrial ecology; valorization of waste streams; waste management (including e-waste); climate-water-energy-food nexus; novel materials for environmental, chemical, and energy applications; sustainability and environmental safety; water digitalization, water data science, and machine learning; process integration and intensification; recent developments in green chemistry for synthesis, catalysis, and energy; and original research on contaminants of emerging concern, persistent chemicals, and priority substances, including microplastics, nanoplastics, nanomaterials, micropollutants, antimicrobial resistance genes, and emerging pathogens (viruses, bacteria, parasites) of environmental significance.