Development of photocatalyst by combined nitrogen and yttrium doping

• (Y, N) codoped TiO2 was synthesized by mild one pot hydrothermal method.
• The Y doping concentration was varied from 0.01 to 1.38 at%.
• 0.05% (Y, N) codoped TiO2 shows enhanced visible light photocatalytic activity.
• Compensated and noncompensated ab-initio calculations were performed.
• Calculation results reasonably explained the experimental findings.

Titanium dioxide co-doped with yttrium and nitrogen with different yttrium doping concentration has been synthesized by mild one pot hydrothermal method without any post calcination for crystallization. Irrespective of the yttrium doping concentration, all the synthesized samples were composed of pure anatase phase with good crystallinity. And the synthesized co-doped samples have spherical morphology with uniform particle size distribution. The absorption edge of the co-doped TiO2 was shifted toward visible light region depicting that the intrinsic band gap of TiO2 was affected by the co-doping. Among the different samples, the co-doped sample with 0.05% yttrium doping concentration exhibits enhanced visible light photocatalytic activity by degradation of methylene blue in aqueous solution. Compensated and non-compensated yttrium–nitrogen co-doped TiO2 models were simulated using density functional theory to explain the experimental findings. The calculation results show that the compensated yttrium–nitrogen co-doped TiO2 model may reasonably explain the experimental observations due to its stable configuration, narrowed band gap and enhanced separation of photoexcited carriers.

The simulated compensated YNSUB co-doped TiO2 model can reasonably explain the experimental observations. Calculation results show that substitutional Y at Ti sites and substitutional N at O sites with an oxygen vacancy give stable configuration, reduced band gap, better visible light absorption and enhance separations of photoexcited charge carriers. The experimental observations confirmed the theoretical findings.Figure optionsDownload as PowerPoint slide