title: Some observations on the development of superior photocatalytic systems for application to water purification by the "adsorb and shuttle" or the interphase charge transfer mechanisms.
abstract: Adsorb and shuttle (A/S) and interfacial charge transfer are the two major strategies for overcoming recombination in photocatalysis in this era of nanoparticle composites. Their relationships are considered here. A review of key literature is accompanied by a presentation of three new experiments within the overall aim of assessing the relation of these strategies. The cases presented include: A/S by a high silica zeolite/TiO2 composite, charge transfer (CT) between phases in a TiO2/WO3 composite and both A/S and CT by composites of TiO2 with powered activated carbon (AC) and single-walled carbon nanotubes (SWCNT). The opportunities presented by the two strategies for moving toward photocatalysts that could support applications for the removal of contaminants from drinking water or that lead to a practical adsorbent for organics that could be regenerated photocatalytically link this discussion to ongoing research here.
authors.affiliation: Department of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada. chlangfo@ucalgary.ca.
authors.forename: Cooper
authors.initials: C
authors.lastname: Langford
authors.affiliation: Department of Chemistry University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada. izadifam@ucalgary.ca.
authors.forename: Maryam
authors.initials: M
authors.lastname: Izadifard
authors.affiliation: Department of Water Pollution Research, National Research Centre, Cairo 12311, Egypt. emadk80@gmail.com.
authors.forename: Emad
authors.initials: E
authors.lastname: Radwan
authors.affiliation: Department of Civil Engineering, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada. gachari@ucalgary.ca.
authors.forename: Gopal
authors.initials: G
authors.lastname: Achari
mesh_terms: D000327:Adsorption / Q000528:radiation effects; D002244:Carbon / Q000302:isolation & purification; D002384:Catalysis / Q000528:radiation effects; D015169:Colony Count, Microbial; D004583:Electrons; D004755:Enterobacteriaceae / Q000302:isolation & purification; D007700:Kinetics; D008027:Light; D013696:Temperature; D014025:Titanium / Q000737:chemistry; D018508:Water Purification / Q000379:methods*; D017641:Zeolites / Q000737:chemistry
chemical_list: C570564:ZSM-5 zeolite; D017641:Zeolites; C009495:titanium dioxide; D002244:Carbon; D014025:Titanium