摘要
The enhanced magnetic and photocatalytic properties of（Fe, Ni）-codoped SrTiO3 with and without oxygen vacancies are investigated using the first-principles calculations based on the density functional theory plus U calculations. It is revealed that the structure phase transition associated with O vacancy imposes significant influence on magnetic and optical properties. The results show that the Ni oxidation state in（Fe, Ni）-codoped SrTiO3 is about 2＋, which is different from that of 4＋ in Ni monodoped SrTiO3 in previous experimental investigations. The presence of O vacancy leads to a semiconductor-half-metal transition in codoped SrTiO3. The（Fe, Ni）-codoped SrTiO3 without O vacancy produces an enhanced magnetization and induces a giant magnetic moment of 3 μB, while a relatively small magnetic moment of 0.36 μB is generated in（Fe, Ni）-codoped SrTiO3 with O vacancy. The origin of the large enhancement of magnetic moment in（Fe, Ni）-codoped SrTiO3 without O vacancy was ascribed to the reduced hybridization in Fe–O bonds and the enhanced hybridization in Ni–O bonds, which modulated antiferromagnetic spin structure. The dispersion of the conduction bands and valence bands of codoped SrTiO3 is enhanced after codoping, which benefits the photocatalytic performance. Furthermore, the（Fe, Ni）-codoped SrTiO3 shows a remarkable red-shift of absorption spectra edge and induces a strong optical absorption in the visible light region, indicating that it could be taken as a potential candidate for photocatalytic materials.
The enhanced magnetic and photocatalytic properties of（Fe, Ni）-codoped SrTiO3 with and without oxygen vacancies are investigated using the first-principles calculations based on the density functional theory plus U calculations. It is revealed that the structure phase transition associated with O vacancy imposes significant influence on magnetic and optical properties. The results show that the Ni oxidation state in（Fe, Ni）-codoped SrTiO3 is about 2＋, which is different from that of 4＋ in Ni monodoped SrTiO3 in previous experimental investigations. The presence of O vacancy leads to a semiconductor-half-metal transition in codoped SrTiO3. The（Fe, Ni）-codoped SrTiO3 without O vacancy produces an enhanced magnetization and induces a giant magnetic moment of 3 μB, while a relatively small magnetic moment of 0.36 μB is generated in（Fe, Ni）-codoped SrTiO3 with O vacancy. The origin of the large enhancement of magnetic moment in（Fe, Ni）-codoped SrTiO3 without O vacancy was ascribed to the reduced hybridization in Fe–O bonds and the enhanced hybridization in Ni–O bonds, which modulated antiferromagnetic spin structure. The dispersion of the conduction bands and valence bands of codoped SrTiO3 is enhanced after codoping, which benefits the photocatalytic performance. Furthermore, the（Fe, Ni）-codoped SrTiO3 shows a remarkable red-shift of absorption spectra edge and induces a strong optical absorption in the visible light region, indicating that it could be taken as a potential candidate for photocatalytic materials.
基金
Supported by the National Natural Science Foundation of China(No.51474011)
the Postdoctoral Science Foundation of China(No.2014M550337)
the Key Technologies R&D Program of Anhui Province(No.1604a0802122,17030901091)
the academic funding project for the top talents of colleges and universities(No.gxbj ZD14)
