光催化灭活是公认的控制病原微生物最具前景手段之一.本文以尿素和硫代巴比妥酸为起始原料,通过热聚合反应制备S掺杂g-C3N4(SCN),随后采用光还原法将Ag纳米粒负载于SCN表面获得新颖的可见光响应型Ag/SCN抗菌材料.对所制备纳米材料进行XRD、SEM、TEM、XPS及UV-Vis DRS表征,并深入探讨其在可见光下灭活大肠杆菌(E.coli)的性能和机制.结果表明,Ag纳米粒均匀且牢固地负载在SCN表面,纳米材料表现出显著增强的可见光响应能力.当负载量为6％时,Ag/SCN-6呈现出最佳的光催化灭菌活性,60 min内能够将6.2 lg CFU·mL-1的E.coli全部灭活.自由基捕获实验结果表明,超氧自由基(·O2-)是灭活过程中最主要活性物种,它协同光生空穴(h+)和羟基自由基(·OH)主导了光催化抗菌的进程.
Preparation of Nano Ag Decorated Sulfur Doped g-C3N4 and Its Photocatalytic Antibacterial Performance
Photocatalytic inactivation has been proved to be one of the most promising strategies for controlling pathogenic microorganisms.Herein,a novel Ag nanoparticles(NPs)decorated sulfur doped g-C3N4(Ag/SCN)composite was successfully prepared by combining thermal polymerization and photoreduction methods using urea and thiobarbituric acid as precursors.The as-prepared samples were characterized by XRD,SEM,TEM,XPS and UV-Vis DRS,the inactivation properties and mechanism against E.coli were investigated in depth.The results indicate that Ag NPs are uniformly and tightly decorated on the surface of SCN and the Ag/SCN composites exhibite significantly enhanced visible light response.When the decorating amount of Ag is 6％,the Ag/SCN-6 achieves the optimal photocatalytic antibacterial activity,which could completely inactivate 6.2 lg CFU·mL-1 of E.coli within 60 min of visible light irradiation.Moreover,active species trapping experiments reveal that the generated superoxide radicals(·O2-)following with holes(h+)and hydroxyl radical(·OH)dominate the photocatalytic antibacterial process.
g-C3N4S dopingnano Ag decorationphotocatalyticinactivationmechanism
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