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

摘要：

在溶剂热法制备ZnO纳米粒子的基础上，利用物理剥离和纳米粒子互剪切作用成功制备了MoS₂/ZnO异质结构纳米复合物。以扫描电子显微镜、透射电子显微镜、X射线能量色散光谱、粉末X射线衍射、拉曼光谱仪、紫外-可见漫反射光谱、光致发光谱等对样品进行了结构形貌和性能表征。结果表明，利用物理剥离和互剪切作用能有效地获得MoS₂/ZnO复合物，复合作用使得MoS₂位于378cm^-1(E¹_2g)和400cm^-1(A_1g)处的两个特征拉曼峰显著增强。复合物中MoS₂含量越少，两个特征拉曼峰强度反而越高，且两峰波数间隔相应减小。可归因于MoS₂含量较低时，ZnO纳米粒子对MoS₂的物理剥离效果越显著，同时，MoS₂体现出良好的分散性和较小的厚度。MoS₂含量对MoS₂/ZnO的发光具有明显的调制作用，显著增强了复合物在可见光区域的吸收。随着MoS₂含量增加，其可见光发光强度迅速减小，紫外峰出现明显的蓝移。纯ZnO对苯酚的降解率最高达90%，而MoS₂/ZnO复合物对苯酚的降解率达100%，复合物对苯酚的最终降解率明显高于纯氧化锌。

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