Effect of co-doping on hydrophilic and photoelectric properties of co-doped titania nanoparticles as a composition of electrode modifier

In this study, nitrogen and cerium co-doped titanium dioxide nanoparticles were prepared by the sol-gel method and were calcined in air at550 °C for 2 hours. Then, the surface glassy carbon electrode was modified and coated with synthesized nanoparticles. The crystalline structure of the nanoparticles was characterized by X-ray diffraction (XRD). The topography, surface roughness and particle size distribution of the coatings were investigated by atomic force microscopy (AFM). Photoelectric properties such as the changes of the absorption edges and band gap values of the nanoparticles were studied by diffuse reflectance spectra (DRS). The hydrophilic property of the coatings was also measured by a contact angle device. In all of the analyses, the effect of nitrogen doping amount on the characteristics of N, Ce co-doped titania samples was investigated. According to the results, the band gap of the co-doped titania samples relative to that of pure titania has been decreased (from  3.21 eV to  2.78 eV) and their surface hydrophilicity has been improved (from 1.01 (deg.min-1) to 1.60 (deg.min-1)). Among the samples the co-doped titania contains the ratio of Ce/Ti: 1% and N/Ti: 0.25%, has the highest amount of anatase phase ( 93.1%), the lowest agglomeration at the surface, the smallest band gap energy ( 2.78 eV) and the highest photo-induced super-hydrophilicity (hydrophilizing rate: 1.60 (deg.min-1)).