title: In Situ Photocatalytic Synthesis of Ag Nanoparticles (nAg) by Crumpled Graphene Oxide Composite Membranes for Filtration and Disinfection Applications.
abstract: Graphene oxide (GO) materials have demonstrated considerable potential in next-generation water treatment membrane-based technologies, which include antimicrobial applications. GO antimicrobial properties can be further enhanced by preloading or chemically generating surface-associated nanoscale silver particles (nAg). However, for these systems, enhanced antimicrobial functionality decreases over time as a function of Ag mass loss via dissolution (as Ag(+)). In this work, we demonstrate facile photocatalytic in situ synthesis of nAg particles by crumpled GO-TiO2 (GOTI) nanocomposites as an approach to (re)generate, and thus maintain, enhanced antimicrobial activity over extended operation times. The described photocatalytic formation process is highly efficient and relatively fast, producing nAg particles over a size range of 40 to 120 nm and with active (111) planes. Additionally, we show in situ surface-based photocatalyzed synthesis of nAg particles at the surface of GOTI nanocomposite membrane assemblies, allowing for simultaneous filtration and disinfection. With ca. 3 log inactivation for both Escherichia coli and Bacillus subtilis, the described membrane assemblies with in situ formed nAg demonstrate enhanced antimicrobial activity compared to the GOTI membrane surface or the support membrane alone. Under typical conditions, the working and operational time (Ag dissolution time) is calculated to be over 2 orders of magnitude higher than the loading (synthesis) time (e.g., 123 h versus 0.5 h, respectively). Taken together, results highlight the described material-based process as a potentially novel antifouling membrane technology.
authors.affiliation: Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
authors.forename: Di
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Translational Imaging, Houston Methodist Research Institute , Houston, Texas 77030, United States.
authors.forename: Minjung
authors.initials: M
authors.lastname: Cho
authors.affiliation: Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
authors.forename: Seung Soo
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
authors.forename: Fuzhong
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
authors.forename: Pratim
authors.initials: P
authors.lastname: Biswas
authors.affiliation: Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
authors.forename: John D
authors.initials: JD
authors.lastname: Fortner
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects; D004203:Disinfection / Q000379:methods; D004926:Escherichia coli / Q000187:drug effects; D005374:Filtration / Q000295:instrumentation*; D006108:Graphite / Q000737:chemistry*; D008567:Membranes, Artificial; D053761:Nanocomposites / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods*; D012834:Silver / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry; D018508:Water Purification / Q000379:methods
chemical_list: D000890:Anti-Infective Agents; D008567:Membranes, Artificial; C009495:titanium dioxide; D012834:Silver; D006108:Graphite; D014025:Titanium