Photocatalytic Decomposition of Synthetic Alizarin Red S by Nickel Doped TiO2

Abstract

The photocatalytic degradation in aqueous medium of the Alizarin Red S (ARS) dye using UV blacklight irradiation (k = 365 nm) over sol-gel nickeltitania doped photocatalyst (0.5-6 wt% Ni) was investigated. The doped semiconductors were characterized by XRD, nitrogen physisorption and UV-Vis diffuse reflectance spectroscopy. High specific surface areas (90 m 2 /g) and small crystallite sizes, which varied with the Ni content, were obtained. No evidence concerning the formation of NiO was observed by XRD, which suggested the deposition of small NiO composites onto the TiO 2 surface. A shift to the visible region of the Eg band gap was obtained by increasing the nickel content in the semiconductors. The substitution of some Ti 4? by Ni 2? cations during the preparation of the photocatalysts was proposed. It was found that the synthesis of the catalysts with 0.5, 1.5, 3 and 6 wt% of Ni resulted in semiconductors that were more active than P25 commercial titania in the photodegradation of ARS.Keywords Dye removal from wastewater Á Ni-doped TiO 2 Á Alizarin Red S dye adsorption Á Sol-gel TiO 2 Á Alizarin Red S (ARS)

Facile one-pot synthesis of nickel-incorporated titanium dioxide/graphene oxide composites: Enhancement of photodegradation under visible-irradiation

“…According to Rodríguez-González et al [7], the structure of NiTiO 3 appeared at a heat treatment temperature of 600C with 6 wt% of Ni. Otherwise, coprecipitation synthesis with up to 5 at % of Ni doping and annealing at hotter than 600C led to the formation of anatase and nickel titanate as major phases and a small amount of NiO appeared at lower annealing temperature (400-500C) [5].…”

“…Loading and doping of TiO 2 with noble metal and transition metal ions such as Pt, Au, Pd, Rh, Ni, Cu, Ag, Co, Cr, Fe, Mo, V, and W could expand its photo-response to the visible region through the formation of impurity levels [4][5][6][7][8][9]. Since metals have lower Fermi level than TiO 2 , photo-excited electrons can be transferred from the TiO 2 conduction band to metal particles on the surface while positive holes are contained in the valence band.…”

“…[10]. Rodríguez-González et al prepared Ni-TiO 2 by a simple sol-gel method for the photo-degradation of alizarin red S dye [7]. Sharma [14][15][16][17][18][19].…”

High dielectric constant nickel-doped titanium oxide films prepared by liquid-phase deposition

“…Ni-doped TiO 2 were wildly investigated currently [12][13][14][15][16]. From a previous study [14], the annealing temperature for anatase-rutile transformation can be lowered by nickel (Ni) doping.…”