Preparation and optical properties of ZnO/ZnS heterostructured nanomaterials

Firstly, Nano-ZnO materials are obtained by hydrothermal method, and Zinc acetate (Zn(CH3COO)2<middle dot>2H2O) is selected as the Zn source, and potassium hydroxide (KOH) is used as the analytical reagent. Secondly, ZnO/ZnS composites are prepared by hydrothermal method using monomer nano-ZnO as a template, thioacetamide (CH3CSNH2) as a sulfur source, hexadecyl trimethyl Ammonium bromide (CTAB) as a surface modifier, and adjusting the molar mass ratio of Zn/S. The structure, morphology, and optical properties of the composite are characterized respectively by XRD, SEM, and PL, and the growth mechanism and fluorescence characteristics of the composite are explored. The results indicate that the crystal structure of the ZnO/ZnS complex is initially a hexagonal wurtzite structure. With the gradual increase of S element concentration, only the crystal plane diffraction peak of sphalerite structure ZnS is shown in the XRD spectrum. Besides, the morphology of the composite also grows from microsphere like to flocculent layered nano-crystals. There are strong characteristic absorption and green light absorption capabilities at 523 nm, and there is a relatively weak ultraviolet emission peak appeared at 380 nm in the PL spectrum. The optical properties and visible light absorption capabilities of the nano-ZnO/ZnS composite are superior to those of the monomer ZnO. Finally, the growth mechanism and luminescence mechanism of ZnO/ZnS are explored at the micro-level.