{"title":"Facile synthesis of activated carbon/titanium dioxide composite and its application for adsorptive/photocatalytic removal of gaseous toluene","authors":"Yang Sun, Younes Ahmadi, Ki-Hyun Kim","doi":"10.1016/j.chemosphere.2024.143638","DOIUrl":null,"url":null,"abstract":"<div><div>The practical utility of activated carbon/titanium dioxide (AC/TiO<sub>2</sub>) composite has been investigated for the abatement of a common aromatic volatile organic compound (VOC), toluene. The adsorption and photocatalytic performance of the prepared AC/TiO<sub>2</sub> composites (ACT-x: x as the theoretical mass ratio (in percent) of AC over TiO<sub>2</sub> ranging from 0% to 10%) is evaluated individually against gaseous toluene using a packed flow tube reactor under varying operational conditions (e.g., relative humidity and gaseous pollutant composition). The presence of AC in the composite significantly increases the adsorption capacity (Q) such as 1.71 mg g<sup>−1</sup> for ACT-10 relative to 0.01 mg g<sup>−1</sup> for ACT-0. The ACT-5, with 3.6% C, exhibits the maximum photocatalytic removal efficiency (X<sub>T</sub> = 93.77%), quantum efficiency (QE; 1.63 × 10<sup>−4</sup> molecules photon<sup>−1</sup>), space time yield (STY; 1.99 × 10<sup>−5</sup> molecules photon<sup>−1</sup> mg<sup>−1</sup>), and specific clear air delivery rate (SCADR; 686.2 L h<sup>−1</sup> g<sup>−1</sup>) among all the ACT compositions tested. ACT-5 exhibits enhanced potential for adsorption and in-situ degradation-desorption to facilitate the removal of VOCs with the reduced yield of by-products. The in-situ diffuse reflectance infrared Fourier transform spectroscopy and gas chromatography-mass spectrometry analyses indicate the formation of several intermediate by-products during the photocatalytic degradation process, including benzyl alcohol, benzaldehyde, benzoic acid, phenol, and alkane species. In addition, the photocatalytic performance of ACT is demonstrated to be superior to those of other TiO<sub>2</sub>-based photocatalysts. Accordingly, the ACT composite is recommended as a promising medium for the abatement of aromatic VOCs in indoor air.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":null,"pages":null},"PeriodicalIF":8.1000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemosphere","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0045653524025384","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
The practical utility of activated carbon/titanium dioxide (AC/TiO2) composite has been investigated for the abatement of a common aromatic volatile organic compound (VOC), toluene. The adsorption and photocatalytic performance of the prepared AC/TiO2 composites (ACT-x: x as the theoretical mass ratio (in percent) of AC over TiO2 ranging from 0% to 10%) is evaluated individually against gaseous toluene using a packed flow tube reactor under varying operational conditions (e.g., relative humidity and gaseous pollutant composition). The presence of AC in the composite significantly increases the adsorption capacity (Q) such as 1.71 mg g−1 for ACT-10 relative to 0.01 mg g−1 for ACT-0. The ACT-5, with 3.6% C, exhibits the maximum photocatalytic removal efficiency (XT = 93.77%), quantum efficiency (QE; 1.63 × 10−4 molecules photon−1), space time yield (STY; 1.99 × 10−5 molecules photon−1 mg−1), and specific clear air delivery rate (SCADR; 686.2 L h−1 g−1) among all the ACT compositions tested. ACT-5 exhibits enhanced potential for adsorption and in-situ degradation-desorption to facilitate the removal of VOCs with the reduced yield of by-products. The in-situ diffuse reflectance infrared Fourier transform spectroscopy and gas chromatography-mass spectrometry analyses indicate the formation of several intermediate by-products during the photocatalytic degradation process, including benzyl alcohol, benzaldehyde, benzoic acid, phenol, and alkane species. In addition, the photocatalytic performance of ACT is demonstrated to be superior to those of other TiO2-based photocatalysts. Accordingly, the ACT composite is recommended as a promising medium for the abatement of aromatic VOCs in indoor air.
期刊介绍:
Chemosphere, being an international multidisciplinary journal, is dedicated to publishing original communications and review articles on chemicals in the environment. The scope covers a wide range of topics, including the identification, quantification, behavior, fate, toxicology, treatment, and remediation of chemicals in the bio-, hydro-, litho-, and atmosphere, ensuring the broad dissemination of research in this field.