黄铁矿型二硫化亚铁论文：黄铁矿型二硫化亚铁 形貌 填充率 表面活性剂 四硫化三铁.docVIP

【关键词】黄铁矿型二硫化亚铁 形貌 填充率 表面活性剂 四硫化三铁 【英文关键词】pyrite FeS2 morphology filling fraction surfactant greigite Fe3S4 黄铁矿型二硫化亚铁论文：铁硫化物纳米晶功能材料的制备与表征 【中文摘要】黄铁矿型二硫化亚铁由于其合适的禁带宽度以及非常高的光吸收系数,非常适合作为太阳能电池材料,并且此种材料已经作为热电池的正极材料。黄铁矿在地球上产量丰富、无毒,非常适合大规模生产以及使用。本论文采用溶剂热法和热注射法分别制备出不同相貌与粒径的单一相黄铁矿型二硫化亚铁粉体。在不同的反应釜填充率下采用溶剂热法制备出了球形与八面体形状的黄铁矿型二硫化亚铁(pyrite)微纳米粉体。通过采用不同的表面活性剂来改善颗粒尺寸与形貌。结果表明采用不同分子量的聚乙烯吡咯烷酮会得到不同形貌的黄铁矿型二硫化亚铁。总体来说,聚乙烯吡咯烷酮浓度较高更容易使得样品颗粒尺寸减小。而采用含羟基的表面活性剂时,很难得到纯黄铁矿型二硫化亚铁,甚至会得到白铁矿型结构的二硫化亚铁,说明过多的羟基会导致相结构的转变。采用阳离子型表面活性剂时对于形貌与颗粒尺寸没有明显的改变,并且颗粒之间有团聚的现象。采用热注射法制备出了立方体外形的纯黄铁矿型二硫化亚铁。发现分散剂三辛基氧膦(TOPO)对于形貌有很好的控制,能够调节颗粒的生长方向。我们以氯化亚铁为铁源,采用三种不同的硫源成功制备出了大小不同的纳米立方体形貌的黄铁矿型二硫化亚铁。采用热注射法,以硫粉作为硫源,采用两种三价铁源制备出了单一相的纯四硫化三铁(greigite)纳米片,不同的铁源制备出的形貌不一。本论文中采用二价铁作为铁源,硫脲作为硫源,首次制备出了纳米片堆叠成的插层状纯相四硫化三铁。 【英文摘要】Iron pyrite (FeS2) is significantly more attractive in both cost and availability than all other compounds for its comparable band gap energy (Eg=0.95eV), and absorption coefficient of105cm-lfor energies greater than1.1eV are also very attractive. In addition, pyrite is composed of very abundant, cheap and nontoxic element.In this thesis, we prepared purity pyrite FeS2using DMSO as solvent at a low temperature in one step using solvothermal method. Many influencing factors such as surfactant and its concentration, maintained time to the morphology of pyrite FeS2were studied. With the same preparated conditions at different filling fraction (60%,70%), we obtained pyrite FeS2with different morphology. The pressure can influence the temperature contrast at top and bottom of the autoclaveand play a role at delivering solute.Polyvinylpyrrolidone (PVP) is essential for the formation of octahedral crystals and reducing particle size. That means the surfactant significantly affected the shape of the final products. When polyvinyl alcohol (PVA) and polyethyleneglycol (PEG) used as surfactants, we could not get the pure pyrite FeS2. That may be because much more hydroxyl group will lead to ferrous iron oxidi