Doped TiO2: effect of doping element on the photocatalytic activity
Doping of TiO2 with various elements increases its photocatalytic activity due to the formation of new energy levels near the conduction band. Photocatalysis involving titanium dioxide is a heterogeneous process in which the surface of the catalyst also plays an important role. The structural properties of TiO2 are influenced by the synthesis method, the doping method, and the dopants. In this work, we compare different doping elements for the photocatalytic activity of titanium dioxide, which synthesized by the sol-gel method. As a doping method, low-temperature underwater plasma was used. Al, Cu, Mo, and W acting as electrodes were chosen as doping elements. The obtained samples were characterized by various techniques. The incorporation of elements leads to distortion of the TiO2 crystal lattice, changing its surface characteristics, and a decrease in the band gap. The introduction of aluminum and copper increases the photocatalytic activity to 70% while doping with Mo and W increases the activity to 96% for 60 minutes of visible light irradiation. Explanations of the effect of various doping elements on the photocatalytic activity of titanium dioxide are presented.