| Effect of Cobalt substitution on the structure and photocatalytic activity of TiO2 under visible light |
| Paper ID : 1186-UFGNSM-FULL |
| Authors: |
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Pejman Monazzam *1, Azadeh Ebrahimian Pirbazari2, Behnam Fakhari Kisomi3 14th Unit - Rouja Building - 21th Alley- Shahid Raja'ee St - Rasht - Gilan - Iran 2Assistant professor, Fouman Faculty of Engineering, College of Engineering, University of Tehran, Iran 3M. Sc student, Caspian Faculty of Engineering, College of Engineering, University of Tehran, P.O. Box 43841-119, Rezvanshahr 43861-56387, Iran |
| Abstract: |
| Environmental cleaning using TiO2 photocatalysts has attracted a great deal of attention. However, the application of TiO2 in water purification is restricted as its intrinsic wide band gap (3.2eV) requires high energy excitation such as UV irradiation, which only composes 5% of solar irradiation. This problem can be reduced by doping TiO2 with foreign elements that allows titania to absorb visible light. In this work TiO2 nanoparticles containing different amounts of cobalt (Co-TiO2) were synthesized by hydrothermal method using titanium (IV) isopropoxide and cobalt chloride as titanium and cobalt precursors respectively. The prepared samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy equipped with energy dispersive X-ray microanalysis (SEM-EDX), diffuse reflectance spectroscopy (DRS) and N2 physisorption techniques. X-ray diffraction (XRD) data showed the prepared samples include pure anatase phase. The XRD patterns of anatase have a main diffractions at 2θ = 25.2°. The presence of cobalt doping in TiO2 nanoparticle’s structure was observed by SEM-EDX and DRS analaysis. The DR spectra of Co-TiO2 Samples showed that the band gap of all Co-TiO2 samples decreased slightly compared with the pure TiO2. N2 physisorption analysis showed a considerable increase in the value of surface area and decrease in the crystallite size with the increase of Co-dopant concentration in TiO2. The photocatalytic activity of the prepared samples was tested for degradation of 2,4-dichlorophenol (2,4-DCP) as a model of organic pollutant under visible light. It was confirmed that the presence of Co in TiO2 structure could enhance the photocatalytic degradation of 2,4-DCP in aqueous suspension. Our results showed the amount of cobalt doping has effect on the photocatalytic activity of the prepared samples. The presence of 0.63% cobalt dopant in TiO2 structure resulted a photocatalyst with the highest activity and 65% degradation of 2,4-DCP was obtained after 180 mins irradiation under visible light. |
| Keywords: |
| Cobalt, TiO2 nanoparticles, Photocatalytic Degradation, 2,4-dichlorophenol |
| Status : Paper Accepted (Oral Presentation) |
