【作者】 高兰；

【导师】 肖奇；

【作者基本信息】 中南大学 ， 材料学， 2011， 硕士

【摘要】 介孔材料由于较高的比表面积、有序的孔道结构等优势,在光催化催化、吸附和生物等领域具有广泛的应用前景。近年来,功能介孔材料的制备及性能研究成为材料研究者的重要研究方向。本论文致力于几种氧化物介孔材料的制备及其性能研究,找到了几种氧化物介孔材料制备的有效方法,并进行了相应介孔样品的性能研究。其主要内容如下：(1)以立方分子筛MCM-48为硬模板,利用“纳米铸造法”合成纯相介孔钒酸铋光催化材料。与传统大颗粒相比,“纳米铸造”介孔BiVO4介孔材料比表面积为22.9 m2·g-1,孔道结构有序,颗粒尺寸较小(约为10nm),有效减少了光生电子和空穴复合的几率,在可见光范围内表现出优良的可见光催化活性,90min内对乙基黄原酸钾的光催化降解率高达78%。(2)利用水热法,以无机钛源硫酸钛、葡萄糖和钨酸钠为原料,通过控制C,W元素摩尔掺杂量,成功制备了可见光响应型金属/非金属共掺杂TiO2介孔材料。样品颗粒大小约为12nm,比表面积约为120m2·g-1左右；样品在可见光区的吸收随着钨掺杂量的增加而不断加强；W6+发挥了电子捕获剂和电子转移的作用,抑制光生电子-空穴的复合,获得了可见光条件下TiO2良好的响应性能；当碳掺杂量为1%、钨掺杂量为10%时,样品在可见光范围内对对苯二甲酸的催化效果最佳。(3)利用分子筛有序孔道的毛细管力,将前躯体吸附进入孔道中,通过[Cu(NH3)4]2+在高比表面积有序介孔分子筛MCM-48孔道内的介孔自组装,成功合成了高比表面的介孔CuO/SiO2复合材料。当Cu:Si=1:2.5时,所制备的主客体复合材料比表面积约为219 m2·g-1,孔径分布与主体材料相似,表现为双峰分布,但都较集中分布于3 nm左右,孔容约为0.3 cm3·g-1,对亚甲基蓝的吸附性能良好,90 min内对乙基黄原酸钾的降解效率高达92%。更多还原

【Abstract】 With the advantage of large specific surface area and ordered pore structure, mesoporous materials showed extensive application prospect in photocatality, adsorption and biology. In the past few years, study on synthesis and properties of functional mesoporus materials had become an important field for researchers. This thesis devoted to fabrication and performance study of types of mesoporous nano-semiconductor photocatalytic materials. Effective methods to synthetize mesoporous materials were found. And performance of as-synthesis samples via different methods was tested. The main contents were discussed as follows:(1) Ordered nanocrystalline mesoporous BiV04 with pure phase was successfully synthesized via nanocasting using cubic MCM-48 molecular sieves as hard template. Comparing with conventional BiVO4 synthesized by hydrothermal method, the nanocasting mesoporous BiVO4 have much higher specific surface of 22.9 m2.g-1, more ordered pore structure and smaller particle size (about 10nm), which decreased the recombination of optical excitation electrons and holes efficiently. As a result, the photocatalytic efficiency of mesoporous BiVO4 for xanthate in 90 mins reached up to 78%.(2) Highly visible light active mesoporous (C、W) doped/co-doped TiO2 were synthesized via hydrothermal method by controlling the dosage of inorganic titanium sulfate, glucose and sodium tungstate. The crytal size of as-synthesized samples was about 12nm and its surface area was greater than 100 m2.g-1. Its visible light absorbance enhanced with the increasing of the W doping amounts. W6+ played the role of the electron capture agent and transferring electron that well photoresponse performance under visible light was got. The photocatalyst doped with C 1.0% and W 10% showed the highest photocatalytic activity under visible light irradiation.(3) By means of capillary force, mesoporous CuO/SiO2 composites with high surface area were triumphantly synthesized via self-assembly basing on [Cu(NH3)4]2+ into the pore of well-organized molecular sieve. The results showed that:at the ratio of Cu:Si=1:2.5, surface area and pore volume of as-synthesized host-guest materials was 219 m2.g-1 and 0.3 cm3.g-1 respectively, and it exhibited a similar bimodal pore size distribution to the host sieve, distributing extensively at about 3nm. It exhibited fine adsorption charactors with methyl blue. Simultaneously, it revealed an excellent photocatalytic activity that 92% of xanthate was degradated in 90 min.更多还原