表面官能团对硫化锌/碳纳米管复合材料的制备及光致发光光谱性能影响

Effect of Surface Functional Groups of Multi-walled Carbon Nanotubes on Preparation and PL Spectra Properties of ZnS/CNTs Nanocomposites

用含有不同表面官能团的碳纳米管（CNTs）,采用回流法制备硫化锌/碳纳米管（ZnS/CNTs）复合光敏材料。利用X射线衍射（XRD）、透射电镜（TEM）和光致发光光谱（PL）等测试手段对ZnS/CNTs复合材料的形貌、物相和发光性质等进行研究。研究表明：ZnS纳米粒子均匀覆盖在碳管表面,为六方纤锌矿结构。CNTs的尺寸以及表面官能团是影响包覆效果的重要因素;使用直径大于30nm、具有COOH表面官能团的CNTs时,ZnS纳米粒子在碳管表面覆盖比例较高,结晶程度明显优于直径8~15nm、无官能团的CNTs。PL光谱分析表明复合材料的发光峰位于393nm和282nm处,分别归属于俘获态发射和带边缘发射。与相同方法制备的ZnS纳米晶体相比,ZnS/CNTs纳米复合材料出现了7nm的蓝移,且整体发射强度更高。

Zinc sulfide / Carbon nanotubes（ ZnS / CNTs） nanocomposites were synthesized via reflux method with raw materials of CNTs with different surface functional groups. The crystal structure,micro morphology and luminescence property of the nanocomposites were characterized by XRD,TEM and PL spectra. The research shows that the ZnS nanoparticles are uniformly covered on the surface of the carbon nanotubes and exhibited hexagonal wurtzite. The size of CNTs and its surface functional groups are important factors to affect the coating effect.Compared to CNTs with diameter 8 ~ 15 nm,no surface functional groups,CNTs with diameter greater than 30 nm,with COOH surface functional groups were better coated by ZnS particles with the most uniform degree. ZnS nanoparticles can be better covered on the surface of carbon nanotubes and achieve better crystallinity when the diameter of CNTs is large and the covalentmodification is used. The PL spectrum analysis shows that the ZnS / CNTs nanocomposites exhibited strong emissions at 393 nm and 283 nm,which is attributed to the trap state and band edge emission,respectively. Compared with the ZnS nanocrystals prepared in the same way,the ZnS / CNTs nanocomposites have a blue shift of 7 nm and the overall emission intensity is higher.