Ag-decorated TiO2 photocatalytic membrane with hierarchical architecture: Photocatalytic and anti-bacterial activities

•Ag-decorated TiO2 photocatalytic membrane with hierarchical architecture was fabricated.•The effect of P-123 and Ag loading on the resulted pores structure were investigated.•Different membrane architectures were fabricated to optimize the membrane performance.•The performance of the membrane was evaluated in the photocatalytic membrane reactor.•Ag–TiO2 membrane exhibited an anti-bacterial property with reusability potential.

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.

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