First-Principles Calculation On Photocatalytic Performance Of Doped Monoclinic BiVO₄

Advances in technology had brought tremendous disaster to our environment,the appearance of semiconductor photocatalysts material makes it possible to change the situation.Because of the excellent quality of the monoclinic Bi VO₄,it came into our vision which can be used to eliminate aqueous and atmospherical pollutants.The paper studied some other types of material based on Bi VO₄,such as C/N doped in it,Bi VO₄ doped by Ag and O/V defected induced in Bi VO₄ by CASTEP of MS software under PWPP based on density function theory（DFT） in this paper,their electronic structure, energy bands, density of states, electron density distribution and optical absorption, reflection, loss spectrum are calculated and analyzed.Results are as follows:1.Doped by nometal monoclinic-Bi VO₄ and optimization, the lattice parameter had increased, the energy band structure analysis finds that after making dope, the band gap significantly reduced.In the model of C-doped Bi VO₄,the results we get says that there are impurity bands between the conduction band and valence band,because of the reason led to such a nature, it is based on C has two factors valence state,and we find the impurity bands near from the top of the valence band,it indicates, it is a type of p-doping,compared to the DOS,all of this are mainly because C 2p and V 3d track electrons contributed to the bands,by analysising optical properties of C-doped model,the ability of response to infrared made a good promotion.N-doped made some similarities,but for the reason N and O has similar atomic radius makes it easier to achieve,and the band gap changes not as much as C-doped.2.After Ag doping,the results showed that in the case of Energy cutoff set to 765 e Vafter,geometry optimization achieved the convergence criteria, combine the map of DOS with the result,it was found properties due to the s and p electronic states induced electrons hybrid,it is sure that the material will play a role in the field of infrared detection in the future.3.The results showed after introduced the defect into the model, the band gap decrease to0.301 e V, and the lattice constants fluctuate within the error range. From the density of status we can see clearly, it is precisely because of s state of orbital electron and d states due to orbital electron distribution. In the aspects of performance response infrared has been improved too.In the results of V defected shows that after the introduction of V defects, above the Fermi level, formed at least three distinct impurity band, the presence of these impurity level make the band gap reduces to 1.51 e V, at the same time it explains the effect of different atomic defects caused by the same kinds of materials.But they all effectively inhibited light-generated electron-hole composites to achieve the effect of improving the photocatalytic efficiency.