关键词: 纳米材料, 复合材料, 纳米粒子, 异质结构, 光化学, 拉曼光谱, 光催化性能

Abstract:

MoS₂/ZnO hetero-nanocomposites were successfully prepared by physical stripping and nanoparticles shearing on the basis of ZnO nanosheets previously prepared by solvothermal method. The structure, morphology, photocatalytic and optical properties of the as-prepared products were characterized using scanning electron microscope, transmission electron microscope, energy dispersive X-ray spectroscopy, X-ray diffractionmeter, Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy and photoluminescence spectrum. The results showed that MoS₂/ZnO composite can be obtained effectively by physical stripping and shearing. The Raman intensity of 378 cm^-1 and 400 cm^-1 of MoS₂ remarkably increased as MoS₂ was combined in ZnO, but the difference between wavenumbers of the two Raman peaks decreased. With decreasing content of MoS₂, the intensity of these two Raman peaks became strong, and the wave number difference between the two Raman peaks decreased accordingly. It can be explained that the physical shearing effect of ZnO nanoparticles on the MoS₂ was significant as MoS₂ at low concentration with the result that MoS₂ showed a good dispersion and a small thickness. MoS₂ concentration had obvious modulation on MoS₂/ZnO luminescence and significantly enhanced the absorption of the composite in the visible region. Increasing MoS₂ content, the visible luminescence intensity decreased rapidly and the ultraviolet luminescence peak appeared blue shift obviously. The degradation rate of phenol by pure ZnO was as high as 90%, while that of MoS₂/ZnO composite was 100%, and the final degradation rate of phenol by the composite was obviously higher than that of pure zinc oxide.

Key words: nanomaterial, composite, nanoparticle, heterostructure, photochemistry, Raman spectra, photocatalytic performance