title: Charge transfer between biogenic jarosite derived Fe3+and TiO2enhances visible light photocatalytic activity of TiO2.
abstract: In this work, we have shown that mining waste derived Fe3+can be used to enhance the photocatalytic activity of TiO2. This will allow us to harness a waste product from the mines, and utilize it to enhance TiO2photocatalytic waste water treatment efficiency. An organic linker mediated route was utilized to create a composite of TiO2and biogenic jarosite. Evidence of FeOTi bonding in the TiO2/jarosite composite was apparent from the FTIR, EFTEM, EELS and ELNEFS analysis. The as prepared material showed enhanced photocatalytic activity compared to pristine TiO2, biogenic jarosite and mechanically mixed sample of jarosite and TiO2under both simulated and natural solar irradiation. The prepared material can reduce the electrical energy consumption by 4 times compared to pristine P25 for degradation of organic pollutant in water. The material also showed good recyclability. Results obtained from sedimentation experiments showed that the larger sized jarosite material provided the surface to TiO2nanoparticles, which increases the settling rate of the materials. This allowed simple and efficient recovery of the catalyst from the reaction system after completion of photocatalysis. Enhanced photocatalytic activity of the composite material was due to effective charge transfer between TiO2and jarosite derived Fe3+as was shown from the EELS and ELNEFS. Generation of OH was supported by photoluminesence (PL) experiments.
authors.affiliation: Flow Process and Rheology Centre, Cape Peninsula University of Technology, South Africa. Electronic address: chowdhurym@cput.ac.za.
authors.forename: Mahabubur
authors.initials: M
authors.lastname: Chowdhury
authors.affiliation: Department of Chemical Engineering, Cape Peninsula University of Technology, South Africa.
authors.forename: Sipiwe
authors.initials: S
authors.lastname: Shoko
authors.affiliation: Electron Microscope Unit, University of the Western Cape, South Africa. Electronic address: fcummings@uwc.ac.za.
authors.forename: Fransciuos
authors.initials: F
authors.lastname: Cummings
authors.affiliation: Flow Process and Rheology Centre, Cape Peninsula University of Technology, South Africa.
authors.forename: Veruscha
authors.initials: V
authors.lastname: Fester
authors.affiliation: Department of Chemical Engineering, Cape Peninsula University of Technology, South Africa. Electronic address: ojumut@cput.ac.za.
authors.forename: Tunde Victor
authors.initials: TV
authors.lastname: Ojumu
mesh_terms: D002384:Catalysis; D005290:Ferric Compounds / Q000737:chemistry*; D008027:Light; D013431:Sulfates / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D013431:Sulfates; D014025:Titanium; D062065:Wastewater; D014874:Water Pollutants, Chemical; C492331:jarosite; C009495:titanium dioxide
keywords: Biogenic jarosite; Charge transfer; Organic pollutant; TiO(2) photocatalysis; Visible light responsive; Water treatment