Effect of nitridation temperature on TiO2 nanotubular structure and its photoelectrochemical performance

To improve light absorption in the visible region and to improve photoelectrochemical (PEC) response; herein, we have presented the doping of titanium dioxide (TiO2) nanotubes with nitrogen. TiO2 nanotubes have been heat treated under the ammonia environment at different temperatures for 3 h. The characterization was carried out using field emission gun scanning electron microscopy, (FEG-SEM), visible ultraviolet (UV-Vis) spectrophotometry. The photoelectrochemical tests of the samples were carried out in a Na2S/Na2SO3 (aq) solution. It was found that the nitrogen doping of titanium dioxide in temperature above 600 °C collapses the tubular structure and decreases the PEC performance. On the other hand, PEC performance improving was obtained from the sample nitrided at the lower temperatura which is related to the formation of lower defects in the structure of TiO2 nanotubes.