Preparation Of ZnS Nanoparticles And Its First Principle Calculation

As a kind of wide bandgap semiconductor,ZnS nano materials have good optoelectronic,photocatalytic and infrared transparent properties.At present,most of the researches on ZnS nano materials are concerned with the preparation of low-dimensional ZnS nano materials,but the theoretical calculation of the micro-properties of ZnS nano materials is very few.Based on the successful preparation of ZnS nanoparticles,the first-principles method was used to study the micro-properties of ZnS various-phase materials.In this paper,ZnS nanoparticles were successfully prepared by hydrothermal method,and relative tests were adopted to characterize their microstructure,surface structure and optical properties.XRD results show that the product is cubic sphalerite structure.The results of SEM showed that the product was spherical nanoparticles with a diameter of about 600 nm.The results of EDS analysis showed that the product elements were Zn and S.The UV-Vis absorption spectra showed that the characteristic peak of the product was blue-shifted at 331 nm compared with the bulk material.Fluorescence spectra show that the product has a certain surface defects.Secondly,the electronic structure and optical properties of the intrinsic and intrinsic defect ZnS materials have been studied by first-principles calculations.The band structure analysis shows that the intrinsic ZnS is a direct bandgap material with a band gap of 2.04 eV.The analysis of density of states shows that the conduction band of ZnS is composed of 4s electrons of Zn,and valence band is composed of 3d and S electrons of Zn and some hybridization occurs.The optical properties of ZnS show that the ZnS has good ultraviolet absorption ability.When S vacancies are present,the band gap of ZnS is narrowed and the absorption of visible light region is enhanced.The absorption of the infrared region is enhanced when the Zn vacancy is present.Finally,the electronic structure and optical properties of ZnS nanowires and ZnS/ZnO nanowires were investigated.The results show that the band gap of the two nanowires is larger than that of the bulk materials,and the UV absorption is enhanced,showing a certain blue shift,which is consistent with the quantum size effect.The ZnS/ZnO core-shell structure,due to the contribution of O 2p electrons at the valence band,has a smaller band gap than ZnS nanowires and enhanced absorption in the visible region.