A first-principles calculation on electronic structure and optical performance of chromium and nitrogen codoped anatase titanium dioxide

In this article, the supercells of pure anatase titanium dioxide, nitrogen and/or chromium doping anatase titanium dioxide were computed using first-principles with the plane-wave ultrasoft pseudopotentials method, and the electronic structure and optical properties of different ions doping models were also studied. The results indicated that the band gap and charge carriers recombination rate of nitrogen and chromium codoped system are all decreased effectively, and the separation of electron-hole pairs becomes more favorable due to impurity energy levels formation in the band gap of anatase titanium dioxide, which could play an important role in enhancing the catalytic activity and visible light absorption of anatase titanium dioxide. Furthermore, the optical absorption curves of nitrogen and chromium codoped anatase titanium dioxide indicate the highest photoresponse for visible-light, which is consistent with the previous experimental results. The above results would be quite helpful for research guiding and further developing of titanium dioxide photocatalyst.