Plasmonic Ag decorated graphitic carbon nitride sheets with enhanced visible-light response for photocatalytic water disinfection and organic pollutant removal

• Published in: Chemosphere (Oxford) 2020-03, Vol.242, p.125201-125201, Article 125201
• Main Authors: Wei, Feng, Li, Jiadong, Dong, Changchang, Bi, Yajun, Han, Xiaojun
• Format: Article
• Language: English
• Subjects: Ag/g-C3N4; Anti-Bacterial Agents - chemistry; Catalysis; Disinfection - methods; Disinfection performance; Escherichia coli - drug effects; Escherichia coli - radiation effects; Graphite - chemistry; Graphite - radiation effects; Light; Metal Nanoparticles - chemistry; Nitrogen Compounds - chemistry; Nitrogen Compounds - radiation effects; Photocatalysis; Photochemical Processes; Photolysis; Silver - chemistry; Silver - radiation effects; Surface plasmon resonance (SPR); Visible light irradiation; Water Pollutants - isolation & purification; Water Pollutants - radiation effects; Water Purification - methods
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2019.125201

Photocatalytic disinfection with high performance is thought to be a promising way for water purification. Herein, plasmonic Ag doped urea-derived graphitic carbon nitride (g-C3N4) composites were fabricated via in-situ photo-deposition at room temperature as the visible-light photocatalyst. Scan electron microscopy and transmission electron microscopy images showed the uniform dispersion of Ag nanoparticles on the surface of g-C3N4 sheet, which facilitated the synergistic effect of antibacterial performance from Ag and photocatalytic property from Ag/g-C3N4 composites. Photocatalytic water disinfection against Escherichia coli with visible light was performed to demonstrate the improved photocatalytic property with assistance of Ag. The 3-Ag/g-C3N4 exhibited the best bactericidal performance by inactivating all bacteria within 120 min with damaged cell membranes of Escherichia coli observed by scan electron microscopy and transmission electron microscopy images. Photoluminescence spectra, steady-state surface photovoltage spectra, photocurrent response, and electrochemical impedance spectra results revealed that Ag nanoparticles inhibited the recombination of photo-generated e− and h+ pairs and further reinforced the photocatalytic performance of g-C3N4. Scavenger experiments indicated that h+ produced on valence band of g-C3N4 dominated the photocatalytic disinfection process against Escherichia coli. This work further proved Ag/g-C3N4 showed great potential in photocatalytic water disinfection under visible-light irradiation. Ag doped urea-derived g-C3N4 composites showed great visible light photocatalytic bacteria disinfection and organic pollutant removal, while the photocatalytic process assisted by SPR effect of Ag NPs was systematically investigated. [Display omitted] •. Novel Ag doped urea-derived g-C3N4 was fabricated via photodeposition method.•. The visible light activity was enhanced by the SPR effect of AgNPs on g-C3N4.•. The visible light disinfection on E.coli and simultaneous RhB removal were achieved.•. The mechanisms of photocatalytic disinfection and RhB removal were proposed.