【作者】 张琪；

【导师】 朱启安；

【作者基本信息】 湘潭大学 ， 无机化学， 2008， 硕士

【摘要】 本论文旨在探索半导体纳米材料硫化铋、二硫化镍的制备方法,研究其微结构、生长机理和光学性质。利用阳极氧化铝（AAO）模板法控制合成了硫化铋、二硫化镍纳米管;同时采用热分解单源前驱体法和表面活性剂辅助回流法合成了硫化铋纳米花,并对其微结构、反应形成机理和光学性质进行了探讨。首先,采用二次阳极氧化法制备了多孔阳极氧化铝（AAO）模板,以高度有序的多孔阳极氧化铝为模板,采用直接渗入自组装方法制备了硫化铋、二硫化镍纳米管。用X-射线衍射（XRD）、能量分散光谱（EDS）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和选区电子衍射（SAED）对样品的结构、成份和形貌进行了表征。结果显示,硫化铋、二硫化镍纳米管直径约40⁵0 nm、长约8¹3μm。二硫化镍纳米管为立方相单晶结构,硫化铋纳米管则为多晶的正交晶系结构。其次,以硝酸铋和十二硫醇为原料,辛酸钠作相转移催化剂,在230℃和250℃热分解单源前驱体烷基硫醇铋,成功合成了Bi₂S₃纳米棒。所得样品用XRD、TEM、EDS、SAED、SEM以及紫外-可见吸收光谱（UV-Vis）进行了表征。结果表明,所得Bi₂S₃纳米棒长约0.4⁵μm、直径约为50¹10 nm,具正交晶相的单晶结构,与230℃制得的纳米棒相比,250℃制得的棒长径比更高、长度更长,但直径相当。其能带间隙由体相的1.3 eV分别增加到2.70、2.85 eV,显示出较强的量子尺寸效应。另外,以硝酸铋和硫脲为反应物,水为溶剂,分别添加PEG400、OP-10、TX-10、Triton X-100作表面活性剂,用回流的方法成功制备出了硫化铋纳米花。用XRD、SEM、TEM、EDS、UV-Vis及SAED等对所制备产物的结构和形貌进行了表征。实验结果表明硫化铋纳米花为正交相结构,晶胞参数为a = 0.382 4 nm,b = 1.232 8 nm,c = 1.118 5 nm。每朵纳米花由数十个直径50¹50 nm、长度500¹200 nm的纳米花瓣自组装而成。表面活性剂对控制Bi₂S₃纳米花的形貌有重要的作用。更多还原

【Abstract】 The dissertation focus on exploring new synthetic methods for nanoscaled semiconducting materials including Bi₂S₃ and NiS₂, on characterzing microstructures and on studying optical properties. Bi₂S₃ and NiS₂ nanotubes were successfully fabricated with controlled morphologies by porous anodic aluminum oxide （AAO） template method. Bi₂S₃ nanoflowers were fabricated via the thermolysis of the single-source precursors and refluxing in the presence of surfactant. Microstructure, growth mechanism and optical properties of all the synthesized nanostructures were studied and discussed.Firstly, porous anodic aluminum oxide （AAO） template was fabricated by two-step anodization. Bi₂S₃ and NiS₂ nanotubes were prepared via a directional infiltration self-assembly route within the nano-holes of the highly ordered AAO template. X-ray powder diffraction （XRD）, energy dispersive spectroscopy （EDS）, scanning electron microscope （SEM）, transmission electron microscope （TEM） and selected area electron diffraction （SAED） were utilized to characterize the structure, compositions and morphology of the samples. The results indicate that the Bi₂S₃ and NiS₂ nanotubes with diameters of 40⁵0 nm and lenghs of 8¹3μm are obtained. The as prepared NiS₂ nanotubes with single crystal structure are cubic phase and Bi₂S₃ nanotubes with polycrystalline structure are orthorhombic phase.Secondly, using Bi（NO₃）₃·5H₂O and C₁₂H₂₅SH as starting materials and NaOOC（CH₂）₆CH₃ as a phase transfer catalyst, Bi₂S₃ nanorods were successfully synthesized by the thermolysis of the single-source precursors bismuth alkylthiolate at 230℃and 250℃. The products were characterized by XRD, TEM, EDS, SAED, SEM, and UV-Vis. The results show that the prepared bismuth sulfide nanorods, with diameters in the range of 50¹10 nm and lengths up of 0.4⁵μm, are orthorhombic phase and single crystal structure. Compared with the nanorods prepared at 230℃, the nanorods prepared at 250℃have higher aspect ratio, larger lengths and almost same diameters. The band gap energy of Bi₂S₃ nanorods are shifted to higher energy of 2.70 and 2.85 eV compared to the typical direct band gap of 1.3 eV of the bulk Bi₂S₃, which exhibits strong quantum size effects. Otherwise, novel flowerlike nanostructures consisting of Bi₂S₃ nanopetals were successfully synthesized by the refluxing with Bi（NO₃）₃·5H₂O and （NH₂）₂CS as reactants and water as solvent in the presence of surfactant including PEG400、OP-10、TX-10、and Triton X-100. Analysis of TEM, SEM, XRD, UV-Vis and SAED shows that the bismuth sulfide nanoflowers are orthorhombic phase and the parameter of crystal cell is a = 0.382 4 nm, b = 1.232 8 nm, c = 1.118 5 nm. The nanoflower is formed by self-assembly of tens of Bi₂S₃ nanopetals with diameters of 50¹50 nm and lengths of 500¹200 nm. It was found that the surfactants plays a key role in determining the morphology of bismuth sulfide nanostuctures.更多还原