Visible light absorption of (Fe, C/N) co-doped NaTaO: DFT+U**Project supported by the National Natural Science Foundation of China (Grant Nos. 51572219 and 11204239), the Project of the Natural Science Foundation of Shaanxi Province, China (Grant Nos. 2015JM1018, 2013JQ1018, and 15JK1714), the Project of Natural Science Foundation of Department of Education of Shaanxi Province, China (Grant No. 15JK1759), and the Science

Abstract

The effects of Fe–C/N co-doping on the electronic and optical properties of NaTaO are studied with density functional theory. Our calculations indicate that mono-doped and co-doped sodium tantalate are both thermodynamically stable. The co-doping sodium tantalate can reduce the energy band gap to a greater degree due to the synergistic effects of Fe and C(N) atoms than mono-doping sodium tantalate, and has a larger optical absorption of the whole visible spectrum. The band alignments for the doped NaTaO are well positioned for the feasibility of hydrogen production by water splitting. The Fe–C co-doping can enhance the absorption of the visible light and its photocatalytic activity more than Fe–N co-doping due to the different locations of impurity energy levels originating from their p–d hybridization effect.