title: Enhanced adsorbability and photocatalytic activity of TiO2-graphene composite for polycyclic aromatic hydrocarbons removal in aqueous phase.
abstract: Photodegradation via titanium dioxide (TiO2) has been used to remove polycyclic aromatic hydrocarbons (PAHs) from environmental media broadly. In this study, a series of TiO2-graphene composites (P25-GR) with different GR weight ratios were synthesized via hydrothermal reaction of graphene oxide (GO) and P25. Their structures were characterized and the proprieties were tested in aqueous phase. Phenanthrene (PHE), fluoranthene (FLAN), and benzo[a]pyrene (BaP) were selected as models of PAHs. The experiment indicated that P25-2.5%GR exhibited enhancement in both adsorption and photodegradation, ∼80% of PAHs were removed after 2h photocatalysis. The influence of photodegradation rate was studied, including PAHs initial concentration and pH. Aromatic intermediates were identified during the reaction process and the degradation pathways were portrayed. This work explored the enhanced photocatalysis performance was attributed to the PAH-selective adsorbability and the strong electron transfer ability of the composite. The analysis of the degradation intermediates confirmed that the reaction proceeded with the formation of free radicals, leading to the gradual PAH mineralization.
authors.affiliation: State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310028, China.
authors.forename: Hongzhen
authors.initials: H
authors.lastname: Bai
authors.affiliation: Institute of Chemical Biology and Pharmaceutical Chemistry, Zhejiang University, Hangzhou 310028, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Industrial Control Technology, College of Control Science and Engineering, Zhejiang University, Hangzhou 310028, China. Electronic address: hj_zhang@zju.edu.cn.
authors.forename: Hongjian
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Institute of Chemical Biology and Pharmaceutical Chemistry, Zhejiang University, Hangzhou 310028, China. Electronic address: tangguping@zju.edu.cn.
authors.forename: Guping
authors.initials: G
authors.lastname: Tang
mesh_terms: D000327:Adsorption; D001580:Benzopyrenes / Q000737:chemistry; D002384:Catalysis; D004785:Environmental Pollutants / Q000737:chemistry; D052918:Environmental Restoration and Remediation; D005449:Fluorenes / Q000737:chemistry; D005609:Free Radicals; D006108:Graphite / Q000737:chemistry; D007700:Kinetics; D010087:Oxides / Q000737:chemistry; D010616:Phenanthrenes / Q000737:chemistry; D010777:Photochemistry / Q000379:methods*; D010782:Photolysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D001580:Benzopyrenes; D004785:Environmental Pollutants; D005449:Fluorenes; D005609:Free Radicals; D010087:Oxides; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D014867:Water; C009495:titanium dioxide; C007738:fluoranthene; C031181:phenanthrene; D006108:Graphite; D014025:Titanium
keywords: Adsorption; PAHs; Photocatalysis; TiO(2) graphene composite