Charge transfer between biogenic jarosite derived Fe 3+ and TiO 2 enhances visible light photocatalytic activity of TiO 2

• Published in: Journal of environmental sciences (China) 2017-04, Vol.54, p.256-267
• Main Authors: Chowdhury, Mahabubur, Shoko, Sipiwe, Cummings, Fransciuos, Fester, Veruscha, Ojumu, Tunde Victor
• Format: Article
• Language: English
• Subjects: Catalysis; Ferric Compounds - chemistry; Light; Sulfates - chemistry; Titanium - chemistry; Waste Disposal, Fluid - methods; Waste Water; Water Pollutants, Chemical - chemistry
• ISSN: 1001-0742
• DOI: 10.1016/j.jes.2015.11.038

In this work, we have shown that mining waste derived Fe can be used to enhance the photocatalytic activity of TiO . This will allow us to harness a waste product from the mines, and utilize it to enhance TiO photocatalytic waste water treatment efficiency. An organic linker mediated route was utilized to create a composite of TiO and biogenic jarosite. Evidence of FeOTi bonding in the TiO /jarosite composite was apparent from the FTIR, EFTEM, EELS and ELNEFS analysis. The as prepared material showed enhanced photocatalytic activity compared to pristine TiO , biogenic jarosite and mechanically mixed sample of jarosite and TiO under 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 TiO nanoparticles, 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 TiO and jarosite derived Fe as was shown from the EELS and ELNEFS. Generation of OH was supported by photoluminesence (PL) experiments.