Insights into efficient removal of gaseous p-xylene using cerium-doped ZnO nanoparticles through photocatalytic oxidation. Issue 2 (8th December 2020)

• Record Type: Journal Article
• Authors: Cheng, Zhuowei; Wang, Junjie; Chen, Dongzhi; Yu, Jianming; Zhang, Shihan; Wang, Shuang; Dai, Yunfei
• Is Part Of: Catalysis science & technology. Volume 11:Issue 2(2021)
• Page Start: 612
• Page End: 623
• Publication Date: 2020-12-08
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d0cy01140a
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Novel Ce-doped ZnO exhibited excellent photocatalytic activity for decomposing VOCs under VUV light. Abstract : Volatile organic compounds (VOCs) are considered to be the main cause of air pollution and should be controlled strictly. Vacuum ultraviolet combined with cerium (Ce)-doped ZnO as the catalyst was investigated for the removal of para -xylene ( p -xylene). Based on scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction analysis, the particle size decreased after cerium in the form of Ce 3+ and Ce 4+ was doped into the ZnO crystal structure. An improved photocatalytic activity (higher p -xylene removal efficiency) was obtained at 0.96% Ce doping, 351 °C calcination temperature, and 339 min calcination duration. Based on the investigation of process parameters, the removal efficiency of p -xylene reached 100% with an initial concentration of 150 mg m −3, a relative humidity of 50%, and a residence time of 60 s. The ozone utilization extent was 96%, suggesting that the remaining ozone after the photocatalysis of p -xylene could be well controlled. Four different kinetic rate equations were used, suggesting that p -xylene and water molecules competed for the same active site. Mechanism analysis suggested that four types of oxidation contributed jointly to the removal of p -xylene and they followed this order: oxidation by the reactive species (RS, mainly ˙OH, O3 and O( 1 D)) > oxidation by the synergistic interactions among photolysis, RS and h + > transformation by direct photolysis > oxidation by h + .