Photocatalytic Degradation of Ofloxacin in Wastewater Using Mg, Ni CO-Doped TiO2 Catalyst

Abstract

The present work uncovers the preparation and characterization of Mg-Ni co-doped TiO2 for the degradation of ofloxacin (OFX) in solar irradiation. The powdered form of the samples were prepared by wet impregnation method and then characterized by using XRD, FE-SEM, UVDRS and FT-IR. XRD confirms the presence of Mg, Ni in doped TiO2. For TMg1.0 Ni 2.0 the intensity of the diffracted peaks in XRD pattern was maximum. FE-SEM confirmed the spherical morphology of the doped TiO2 samples and the particle size was in the range of 20-60 nm. UVDRS data confirmed the band gap of pure TiO2 and also displayed that the band gap reduces on doping. FT-IR confirms the stretching and bending bands of the various bonds present in the sample of undoped and doped TiO2 with the literature. Impact of different parameters like dose of the catalyst, effect of concentration of OFX solution, effect of pH was also studied. By optimizing with pure TiO2 it was found that 2 g/l of the catalyst dose was required and 40 ppm concentration of OFX solution maintained at pH 5 displayed maximum degradation. Results also show that TMg1.0Ni2.0 (2 g/l) displayed maximum degradation (90%) of Ofloxacin solution within 3h at pH 5. Photocatalytic activity of the Mg, Ni (TMg1.0Ni2.0, TMg2.0Ni1.0, and TMg1.5Ni1.5) co-doped catalyst was higher than pure TiO2. The degradation obeys first order kinetics and the rate constant for pure TiO2 and TMg1.0Ni2.0, TMg2.0 Ni1.0, and TMg1.5Ni1.5 doped TiO2 are 0.0047, 0.0133, 0.0124, 0.0116 min-1 respectively. The kinetics of degradation also proved that rate constant increases on doping.