PEO聚合物诱导下多形态钼氧化物的可控制备及其调控机理研究

Molybdenum oxides possess a variety of potential applications in chemical synthesis, petroleum refining, recording media and sensors because of its unique catalytic activity, elctroluminescent and photoluminescenceand. It is vital for the performance of molybdenum oxides to regulate and control the morphology, size and structure of the crystal of molybdenum oxides. Recently the polymeric system has been adopted as template or confinement reactor for nao-and micro-fabrication. Polymers with differrent morphologies and tunable sizes in the different conditions can be modified to enhance interactions and be easy removed by dissolution with a solvent or by calcification. Based on the unique properties of molybdenum oxides and polymer application in the biomineralization of inorganic compounds, a brand-new comprehensive subject named as "PEO polymer-controled synthesis of molybdenum oxides: structure diversity and mechanism research" has been brought forth by us. In this subject, using "Molybdenum oxides nano materials assembly and crystallization process " as the main line, some basic researches including the conformation of molybdenum precursor solution, the Nucleation and growth of molybdenum oxides in the PEO polymeric systems, and the biomineralization of molybdenum oxides would have been studied out.Through the study mentioned above, we can obtain the regulation measures of molybdenum oxides with multi-morphologies and comples structures, fulfill the controllable synthesis of special molybdenum oxides,and ultimately reveal the structure diversity and the regulation mechanism of molybdenum oxides in the PEO polymeric systems. Furthermore,the novel synthesization technology for nano-and micro-molybdenum oxides and organic/inorganic hybrid materials would come into being ,and be also employed for growth of a variety of nano- and micro-transition metal oxide materials in the future.

钼氧化物具有电/光致发光和光催化等特殊性能，对其结构/晶形的调控是获取优异性能钼氧化物的关键。基于PEO聚合物在无机物矿化和功能晶体材料等方面的应用，申请人提出"PEO聚合物诱导下多形态钼氧化物的可控制备及其调控机理研究"的新课题。以"PEO聚合物诱导下钼氧化物纳米材料组装和晶化过程"为主线，开展钼躯物在水溶液中存在形态、PEO聚合物诱导下钼氧化物晶体成核/生长、钼氧化物矿化等方面的基础性研究，探讨钼氧化物晶体结构/晶形的影响因素，揭示钼氧化物晶体形貌渐变规律和PEO聚合物对钼氧化物的调控机理，建立钼氧化物形态/结构/尺寸的调控手段，实现多形态钼氧化物的可控制备和功能化。开展本课题的研究，可形成纳/微米钼氧化物及其杂化材料的制备新技术，进而可拓展到多种过渡金属氧化物材料的制备，对聚合物诱导无机物矿化理论和过渡金属功能材料调控制备具重要的科学意义和实际应用价值。

钼氧化物具有电/光致发光、光催化和导电等特殊性能，对其结构/晶形的调控是获得优异性能钼氧化物的关键。本项目以“PEO聚合物诱导下钼氧化物纳微米材料组装和晶化过程”为主线，开展PEO聚合物诱导下钼氧化物晶体成核/生长、钼氧化物矿化和应用等方面的基础性研究，探讨钼氧化物晶体结构/晶形的影响因素，揭示钼氧化物晶体形貌渐变规律和PEO聚合物对钼氧化物的调控机理，建立钼氧化物形态/结构/尺寸的调控手段，实现多形态钼氧化物的可控制备和功能化。.考察了双氧水和钼的配比、搅拌、反应温度、PEG聚合物浓度、反应时间、PEG分子量等因素对含钼杂化物形貌结构的影响，揭示了含钼杂化物晶体形貌渐变规律以及PEG聚合物对含钼杂化物的调控机理。.重要结果和结论如下：.(1) 当双氧和钼的配比为7.84倍时，杂化物的形貌易于调控，形貌比较规整均一。在PEG聚合物存在下，加热过程中外力搅拌对产物形貌影响较大。搅拌所制备的产物为十八面体，未搅拌所制备的产物为球形，但搅拌容易扰乱PEG聚合物在水溶液中的自组装行为，导致形貌重复性变差。.(2) 在没有添加PEG聚合物情况下，反应温度对所合成样品的形貌及物相影响不大；在PEG聚合物存在下，反应温度对所合成样品的形貌有显著的影响。随着反应温度的升高，形貌由球形向立方体转变。.(3) PEG聚合物浓度对含钼杂化物形貌/结构/物相组成影响最为显著。随着聚合物浓度的增加，产物的形貌由板片状-带状-球形和带状混合状态-球状-球形和立方体混合状态-立方体转变；产物的物相由H2MoO5向MoO3•H2O再向无定型状态转变；产物的颜色由黄色向绿色再向蓝色以及深蓝色转变。产物的价态由六价钼向低价钼转变。.(4) PEG不是以简单的物理吸附或者包夹形式与过氧钼酸分子结合的，而是PEG中的部分-OH和过氧钼酸分子发生了强烈的化学键合。PEG聚合物不仅是模板剂，表面活性剂，而且也是弱的还原剂。. 通过本课题研究，部分研究成果发表在Crystal Growth & Design、Journal of Alloys and Compounds、Journal of Energy Chemistry等刊物上。实现了对纳/微米钼氧化物及其杂化材料的有效调控，制备的系列钼氧化物（如MoO2/C微球、MoO2/Mo2C/C微球等）作为电极材料可应用于锂电池领域。