Effects of gas adsorption on electronic structure and optical properties of V-doped graphene
Based on the generalized gradient approximation(GGA)under the density functional theory system,the first-principles method was used to investigate the effect of gas molecule adsorption on the adsorption ener-gies,energy band structures and optical properties of the V-doped graphene.The band structure calculation showed that the band gap of V-doped graphene adsorbing N02 gas molecule is increased from 0 eV to 0.368 eV,and its material property has also changed from metal to semiconductor.However,the band gaps of V-doped graphene adsorbing CO and NH3 molecules are almost unchanged.The adsorption energies of the three ad-sorption(NO2,CO,NH3)configurations are-8.499 eV,-2.05 eV and-2.01 eV,respectively,indicating that V-doped graphene has the best adsorption effect on NO2 gas molecules.Furthermore,the optical properties of intrinsic and doped graphene when adsorbing NO2 gas molecules were calculated.The results displayed that the dielectric absorption peak value of graphene is increased with V doping and adsorbing NO2 gas,and the die-lectric peak position is moved to the low energy region;Intrinsic graphene can only absorb ultraviolet light,and V-doped graphene can significantly improve the spectral range of light absorption after absorbing NO2 mole-cules.The photoconductivity of graphene can be significantly enhanced by the doping and adsorption,and the photocurrent can be generated in the infrared and visible light regions.The above research results show that the electronic structures and optical properties of V-doped graphene adsorbing NO2 have been significant changed,and it can be applied as an optical gas sensing material to detect NO2 gas.
国家科技期刊平台
NSTL
万方数据
维普
