title: Graphene and g-C3N4 nanosheets cowrapped elemental α-sulfur as a novel metal-free heterojunction photocatalyst for bacterial inactivation under visible-light.
abstract: A new class of metal-free heterojunction photocatalysts was prepared by wrapping reduced graphene oxide (RGO) and g-C3N4 (CN) sheets on crystals of cyclooctasulfur (α-S8). Two distinctive structures were fabricated by wrapping RGO and CN sheets in different orders. The first was RGO sheets sandwiched in heterojunction of CN sheets and α-S8 (i.e., CNRGOS8), while the second structure was the other way around (i.e., RGOCNS8). Both structures exhibited antibacterial activity under visible-light irradiation. CNRGOS8 showed stronger bacterial inactivation than RGOCNS8 in aerobic conditions. However, RGOCNS8 was more active than CNRGOS8 under anaerobic condition. A possible mechanism was proposed to explain the differences between photocatalytic oxidative inactivation and reductive inactivation. As a proof-of-concept, this work could offer new inroads into exploration and utilization of graphene sheets and g-C3N4 sheets cowrapped nanocomposites for environmental applications.
authors.affiliation: Department of Chemistry and Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong , Shatin, N.T., Hong Kong, China.
authors.forename: Wanjun
authors.initials: W
authors.lastname: Wang
authors.forename: Jimmy C
authors.initials: JC
authors.lastname: Yu
authors.forename: Dehua
authors.initials: D
authors.lastname: Xia
authors.forename: Po Keung
authors.initials: PK
authors.lastname: Wong
authors.forename: Yecheng
authors.initials: Y
authors.lastname: Li
mesh_terms: D001419:Bacteria / Q000528:radiation effects*; D002384:Catalysis; D006108:Graphite / Q000737:chemistry*; D008027:Light; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013455:Sulfur / Q000737:chemistry*
chemical_list: D013455:Sulfur; D006108:Graphite