Photocatalytic mineralisation of methylene blue using buoyant TiO2-coated polystyrene beads

Fabiyi, Malcolm; Skelton, Robert L.

doi:10.1016/s1010-6030(99)00250-6

Cited by 181 publications

(74 citation statements)

References 10 publications

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“…Thermal sintering has been previously demonstrated to promote strong adhesion of immobilized TiO 2 to glass supports [21][22][23], although reducing specific surface area of the TiO 2 in the process [24]. Floating photocatalysts synthesized previously have used plastic supports susceptible to photocatalytic degradation [25][26][27][28][29][30], or fragile materials such as perlite [31][32][33], which sink upon breaking. The floating photocatalyst (FPC) composites prepared herein are entirely inorganic and resistant to photodissolution, and thus more suitable towards long term emplacement in a passive treatment system.…”

Section: Resultsmentioning

confidence: 99%

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Leshuk

Krishnakumar

Livera

et al. 2018

Water

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Abstract:Oil sands process-affected water (OSPW), generated from bitumen extraction in the Canadian oil sands, may require treatment to enable safe discharge to receiving watersheds, as dissolved naphthenic acids (NAs) and other acid extractable organics (AEO), identified as the primary toxic components of OSPW, are environmentally persistent and poorly biodegradable. However, conventional advanced oxidation processes (AOPs) are impractically expensive to treat the volumes of OSPW stockpiled in the Athabasca region. Here we prepared floating photocatalysts (FPCs) by immobilizing TiO 2 on glass microbubbles, such that the composite particles float at the air-water interface for passive solar photocatalysis. The FPCs were demonstrated to outperform P25 TiO 2 nanoparticles in degrading AEO in raw OSPW under natural sunlight and gentle mixing conditions. The FPCs were also found to be recyclable for multiple uses through simple flotation and skimming. This paper thus demonstrates the concept of a fully passive AOP that may be scalable to oil sands water treatment challenges, achieving efficient NA reduction solely through the energy provided by sunlight and natural mixing processes (wind and waves).

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Section: Resultsmentioning

confidence: 99%

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Leshuk

Krishnakumar

Livera

et al. 2018

Water

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“…The same approach was used when attaching nanocrystallyne TiO 2 to the maleic anhydride-polyethylene copolymer film [4]. Several recent studies have reported the photocatalytic degradation of methylene blue on TiO 2 -polstyrene [5], the abatement of porphyrins on polystyrene [6] and the use of anatase on plastic surfaces as photocatalyst [7]. A recent review reports the fixation by plasma methods of TiO 2 on polymer films [8].…”

Section: Introductionmentioning

confidence: 99%

Stabilization mechanism of TiO2 on flexible fluorocarbon films as a functional photocatalyst

Mielczarski¹,

Mielczarski²,

Laub³

et al. 2006

Journal of Molecular Catalysis A: Chemical

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The repetitive discoloration kinetics of the azo-dye Methyl Orange (taken as a model organic compound) was followed under solar simulated radiation (90 mW/cm 2 ) to assess the performance of the TiO 2 /Tedlar ® composite photocatalyst. The influence of solution parameters on the photo-discoloration process: pH, dye concentration, applied light intensity and concentration of H 2 O 2 were systematically investigated. During the photocatalysis a modification occurs in the TiO 2 /Tedlar ® composite due to the TiO 2 interaction with the Tedlar ® film. Physical insight is given for the stabilization mechanism of the TiO 2 particles in the Tedlar matrix based on the data obtained by X-ray photoelectron spectroscopy (XPS). The F 1s peak of the Tedlar film indicates that the TiO 2 is loaded on the Tedlar fluoro-groups. The loading of TiO 2 on the 75 m thick Tedlar ® film was ∼0.9% (w/w) as determined by atomic absorption spectrophotometry (AAS). Attenuated total reflection infrared spectroscopy (ATRIR) shows no formation of additional bands within the photodiscoloration reaction. This shows that an efficient catalysis taking place on the TiO 2 /Tedlar ® surface. The rugosity (mean square roughness, rms) of the TiO 2 /Tedlar ® film was determined by atomic force microscopy (AFM) to be 19.7 nm. This value remained constant during long-term operation. Transmission electron microscopy (TEM) reports the thickness and coverage of TiO 2 Degussa P-25 on the Tedlar ® surface before and after photocatalysis.

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“…In most cases, prepared immobilized TiO 2 used solvent-based polymers, such as polythene sheets [10], thin polythene films [11], polystyrene (PS) beads [12], expanded polystyrene (EPS) beads [13], cellulose microspheres [14], fluoro polymer resins [15], polyethylene terephthalate (PET) bottles [16], polypropylene (PP) granules [17], cellulose fibers [18], polypropylene fabric (PPF) [19], polyvinyl chloride (PVC) [20], polycarbonate (PC), poly(methyl methacrylate) (PMMA) [21], polyvinyl acetate (PVAc) [22], poly(styrene)-co-poly(4-vinylpyridine) (PSP4VP) [23], rubber latex (an elastic hydrocarbon polymer) [24], parylene and tedlar [25]. Recently, water-based polymer binders have shown a vast potential of usage in immobilized TiO 2 for commercialization because they are environmentally friendly and economic.…”

Section: Introductionmentioning

confidence: 99%

The Preparation and Characterization of Immobilized TiO2/PEG by Using DSAT as a Support Binder

et al. 2016

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Immobilized TiO 2 was prepared by adding a small composition of polyethylene glycol (PEG) as a binder, and this paper reported for the very first time the formation of C=O from oxidized PEG, which acted as an electron injector in enhancing photoactivity. Water-based TiO 2 with PEG formulation was deposited by using a brush technique onto double-sided adhesive tape (DSAT) as a support binder to increase the adhesiveness of immobilized TiO 2 . The photocatalytic activity of immobilized TiO 2 -PEG was measured by photodegradation of 12 mg·L −1 methylene blue (MB) dye. The optimum condition of immobilized TiO 2 -PEG was observed at TiO 2 /PEG-2 (TP2) with 10:0.1 for the TiO 2 /PEG ratio, which resulted in a 1.8-times higher photodegradation rate as compared to the suspension mode of pristine TiO 2 . The high photodegradation rate was due to the formation of the active C=O bond from oxidized PEG binder in immobilized TiO 2 -PEG as observed by Fourier transform infrared and X-ray photoelectron spectroscopy analyses. The presence of C=O has escalated the photoactivity by forming an electron injector to a conduction band of TiO 2 as proven by higher photoluminescence intensity obtained for TP2 as compared to pristine TiO 2 . The TP2 sample has also increased its adhesiveness when DSAT is applied as a support binder where it can be recycled up to eight times and comparable to recent photocatalysis cycle developments.

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Photocatalytic mineralisation of methylene blue using buoyant TiO2-coated polystyrene beads

Cited by 181 publications

References 10 publications

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Stabilization mechanism of TiO2 on flexible fluorocarbon films as a functional photocatalyst

The Preparation and Characterization of Immobilized TiO2/PEG by Using DSAT as a Support Binder

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