Paper Title
Modification of Crystalline and Photocatalytic Properties of Tio2 by NB Doping: The Influence of Annealing Temperatures

Abstract
Niobium doped-titanium dioxide (TiO2) thin films were prepared via sol-gel spin coating method at different annealing temperatures. XRD spectra confirmed all of the films exist in anatase phase which is the most preferable phase for photo catalysis. The film annealed at 550 °C was revealed to has the highest crystallinity. Nb-doped TiO2 were proceeded with visible-light photo catalytic activity test where the film annealed at 550 °C shows highest visible-light photo catalytic performance among all samples with percentage degradation of 96.9%. The reaction rate of Nb-doped TiO2 was 1.73 x 10-2 min-1 which is the highest and fastest than the rest of the films. From this presented work, Nb-doped TiO2annealed at 550 °C are promising for an enhanced visible-light photo catalysis. Keywords - Titanium Dioxide; Niobium; Spin Coating; Annealing Temperatures; Photocatalytic