title: Ag-decorated TiO2 photocatalytic membrane with hierarchical architecture: photocatalytic and anti-bacterial activities.
abstract: Ag-decorated TiO2 (Ag-TiO2) photocatalytic membranes have been fabricated by using Pluronic P-123 as a pore-forming and structure-directing agent. Six different hierarchical architectures were obtained by multilayer coating of different Ag-TiO2 sols. The porous structure of the resulting layers could be fine-tuned by altering the amounts of P-123 and AgNO3 added during the preparation of TiO2 sols. Physico-chemical and morphological properties of different Ag-TiO2 layers were thoroughly investigated. Ag nanoparticles were successfully incorporated into the TiO2 matrix. The Ag-TiO2 membranes possessed multi-functionality of membrane retention, Ag-enhanced TiO2 photocatalytic activity and anti-bacterial action. They were evaluated through experiments using a batch reactor and a photocatalytic membrane reactor (PMR). The best performing membrane was able to remove up to 1007 mg m(-2) h(-1) of Rhodamine B in the PMR. Two phenomena (photocatalytic degradation and adsorptive-membrane retention) that were responsible for the RhB removal were evaluated. In the batch reactor operated in dark, the membranes were able to remove greater than 5-logs of Escherichia coli. The membrane with the highest percentage of Ag incorporated was able to remove close to 7-logs of E. coli when operated in the PMR.
authors.affiliation: School of Civil and Environmental Engineering, Nanyang Technological University, Block N1, 50 Nanyang Avenue, Singapore 639798, Singapore; Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore.
authors.forename: Ronn
authors.initials: R
authors.lastname: Goei
authors.affiliation: School of Civil and Environmental Engineering, Nanyang Technological University, Block N1, 50 Nanyang Avenue, Singapore 639798, Singapore; Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore. Electronic address: cttlim@ntu.edu.sg.
authors.forename: Teik-Thye
authors.initials: TT
authors.lastname: Lim
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D019149:Bioreactors; D002384:Catalysis; D004926:Escherichia coli / Q000187:drug effects*; D008567:Membranes, Artificial; D055668:Photochemical Processes; D012834:Silver / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D008567:Membranes, Artificial; C009495:titanium dioxide; D012834:Silver; D014025:Titanium
keywords: Anti-bacterial activity; Ceramic membrane; Photocatalytic membrane reactor; Silver nanoparticles; Titanium dioxide