title: Sulfonated graphene oxide-ZnO-Ag photocatalyst for fast photodegradation and disinfection under visible light.
abstract: Synthesis of efficient visible-light-driven photocatalyst is urgent but challenging for environmental remediation. In this work, for the first time, the hierarchical plasmonic sulfonated graphene oxide-ZnO-Ag (SGO-ZnO-Ag) composites were prepared through nanocrystal-seed-directed hydrothermal method combining with polyol-reduction process. The results indicated that SGO-ZnO-Ag exhibited much faster rate in photodegradation of Rhodamine B (RhB) and disinfection of Escherichia coli (E. coli), than ZnO, SGO-ZnO and ZnO-Ag. SGO-ZnO-Ag totally degraded RhB dye and kill 99% of E. coli within 20 min under visible light irradiation. The outstanding performances of SGO-ZnO-Ag were attributed to the synergetic merits of SGO sheets, ZnO nanorod arrays and Ag nanoparticles. Firstly, the light absorption ability of SGO-ZnO-Ag composite in the visible region was enhanced due to the surface plasmon resonance of Ag. In addition, the hierarchical structure of SGO-ZnO-Ag composite improved the incident light scattering and reflection. Furthermore, SGO sheets facilitated charge transfer and reduce electron-hole recombination rate. Finally, the tentative mechanism was proposed and verified by the photoluminescence (PL) measurement as well as the theoretical finite-difference time-domain (FDTD) simulation. In view of above, this work paves the way for preparation of multi-component plasmonic composites and highlights the potential applications of SGO-ZnO-Ag in photocatalytic wastewater treatment field.
authors.affiliation: School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.forename: Kokseng
authors.initials: K
authors.lastname: Ng
authors.forename: Darren Delai
authors.initials: DD
authors.lastname: Sun
mesh_terms: D002384:Catalysis; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D006108:Graphite / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity; D008027:Light; D010087:Oxides / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity; D010782:Photolysis; D012235:Rhodamines / Q000737:chemistry; D012834:Silver / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity
chemical_list: D010087:Oxides; D012235:Rhodamines; D014874:Water Pollutants, Chemical; D012834:Silver; D006108:Graphite; D015032:Zinc; C029773:rhodamine B
keywords: Disinfection; Photodegradation; Plasmonic photocatalyst; SGO–ZnO–Ag