Photocatalytic degradation of dyes and organic contaminants in water using nanocrystalline anatase and rutile TiO₂

Abstract

Nanocrystalline TiO 2 was synthesized by controlled hydrolysis of titanium tetraisopropoxide. The anatase phase was converted to rutile phase by thermal treatment at 1023 K for 11 h. The catalysts were characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), Fourier-transform infrared absorption spectrophotometry (FT-IR) and N 2 adsorption (BET) at 77 K. This study compare the photocatalytic activity of the anatase and rutile phases of nanocrystalline TiO 2 for the degradation of acetophenone, nitrobenzene, methylene blue and malachite green present in aqueous solutions. The initial rate of degradation was calculated to compare the photocatalytic activity of anatase and rutile nanocrystalline TiO 2 for the degradation of different substances under ultraviolet light irradiation. The higher photocatalytic activity was obtained in anatase phase TiO 2 for the degradation of all substances as compared with rutile phase. It is concluded that the higher photocatalytic activity in anatase TiO 2 is due to parameters like band-gap, number of hydroxyl groups, surface area and porosity of the catalyst.

Ultra-rapid photocatalytic activity of Azadirachta indica engineered colloidal titanium dioxide nanoparticles

“…The titanium dioxide nanoparticles' time-dependent treatment with methyl red dye solution decreases peak intensity was compared with control (methyl red solution) (Sankar et al 2014a). The titanium dioxide nanoparticles act as an excellent photocatalytic agent, due to their strong oxidizing power, non-toxicity and long-term stability (Tayade et al 2007). The size, charge and morphology of synthesized nanoparticles might influence the enriched photocatalytic degradation activity.…”

“…This SPR arises from the coherent existence of free electrons in the conduction band due to the small particle size. Among abundant metal oxide nanoparticles, semi-conductive titanium dioxide nanoparticles have apprehensive interest due to their distinctive properties and numerous potential technological applications such as ability to decompose chemical compounds, act as a biosensor, photocatalysis, memory devices, solar cell sensors, super hydrophilic and antibacterial properties (Tayade et al 2007). …”

Sol-Gel Preparation of Nanocrystalline Titania Photocatalyst for Water Treatment Using N-Butoxide Modified With Ethyl Acetoacetate in Various Amounts

“…2 Also, the higher number of surface catalytic sites enables less recombination of electron-hole pairs, which is the rate-determining step in the photocatalytic degradation. 36 Again, the sample with the greatest specific surface area was the unchelated one. Therefore, photocatalytic activity is in concordance with bandgap and specific surface area values.…”

“…Electron-hole pair generation is dependent on bandgap, 36 influencing the intensity of light that could be absorbed. Therefore, it is expected that the sample with a lower bandgap, i.e.…”

Visible Light Mediated Degradation Studies of Methylene Blue by Nano Tio2 Synthesized by Azardica Indica Leaf Extract

“…TiO 2 film of 80% anatase and 20% rutile was prepared through wet chemical method was used for methylene blue degradation (Rosu et al 2009). Nanocrystalline TiO 2 synthesized by hydrothermal treatment using titanium isopropoxide was used to degrade methylene Blue (Tayade et al 2007). There is no much research reported on degradation of methylene blue by green route synthesized nano TiO 2 .…”