Difference of visible-light photocatalytic activity behaviors between nitrogen- and phosphorus-doped titanium(IV) oxide films

The property of phosphorus (P)-doped titanium(IV) oxide (TiO2) films prepared using phosphide was compared with that of nitrogen (N)-doped TiO2 films prepared using nitride. X-ray diffraction analysis showed that the crystallite size of P-doped TiO2 film was larger than that of N-doped TiO2 film. The data also indicated the low crystallinity of P-doped TiO2 film. Optimal calcination temperatures for phenol photodegradation were observed at 475 °C for P-doped TiO2 films and 550 °C for N-doped TiO2 films. The difference in the optimal temperature is discussed in terms of the change in crystallinity and crystallite size. Phenol degradation experiments in the repeated use of P- and N-doped TiO2 films revealed the feature of the stability.