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聚苯胺改性负载型纳米二氧化钛的研究 总被引:1,自引:0,他引:1
采用悬浮聚合法制备聚苯乙烯微珠载体,通过矿化接枝技术将溶胶-凝胶法制备的纳米二氧化钛负载在微珠载体上,制成负载型纳米二氧化钛光催化剂。利用导电聚苯胺对负载型纳米二氧化钛光催化剂进行可见光改性研究,通过XRD,SEM等方法对负载型纳米二氧化钛光催化剂进行表征;通过光催化降解甲基橙实验评价了导电聚苯胺改性负载型纳米二氧化钛光催化剂在可见光条件下的光催化活性。实验结果表明:导电聚苯胺对负载型纳米二氧化钛光催化剂的改性,可有效改善负载型纳米二氧化钛光催化剂在可见光条件下的光催化性能,降解率提高了24.5%。 相似文献
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为综合二氧化钛、钒酸铋光催化剂的性能,制备了二氧化钛-钒酸铋复合光催化剂,并以布洛芬为目标降解物,与二氧化钛、钒酸铋光催化剂的光催化性能进行了对比。以钛酸丁酯为原料,加入无水乙醇、盐酸、去离子水,采用凝胶法制备了二氧化钛光催化剂;以五水硝酸铋、偏钒酸铵为原料,加入浓硝酸、氢氧化钠,制备了钒酸铋、二氧化钛-钒酸铋复合光催化剂。此制备方法简便、高效。在可见光照射下,使用二氧化钛、钒酸铋、二氧化钛-钒酸铋3种光催化剂对布洛芬进行光催化降解,并将3种光催化剂分别联合过氧化氢对布洛芬进行光催化降解,考察了3种光催化剂的光催化性能。结果表明,未加入过氧化氢条件下,3种光催化剂的光催化性能由大到小的顺序为二氧化钛-钒酸铋、二氧化钛、钒酸铋;加入电子捕获剂过氧化氢后,提高了光催化剂降解布洛芬的效率,减少了电子-空穴对的复合速度,并且3种光催化剂的光催化性能由大到小的顺序为二氧化钛-钒酸铋、钒酸铋、二氧化钛。 相似文献
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二氧化钛光催化剂的应用比其他半导体光催化剂更广泛,但它也有一定的局限性,因此需对二氧化钛的性能进行改进,可以拓宽二氧化钛的光响应范围,并提高光载体的形成、分离和转移效率,消除电子孔组成真空,提高半导体催化剂的光催化性能。着重介绍了提高二氧化钛作为半导体光催化剂的光催化活性的改性方法,包括金属及非金属的掺杂、包覆以及负载等,并对目前的研究成果以及遇到的问题进行了综述,最后就二氧化钛作为半导体光催化剂的未来发展前景进行了简单分析。 相似文献
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采用溶胶-凝胶法制备了镧掺杂二氧化钛光催化剂,并利用莠去津模拟废水考察了其催化性能。在紫外光照射4h条件下探讨了焙烧温度、焙烧时间、镧掺杂量(摩尔百分比)对镧掺杂二氧化钛光催化剂催化性能的影响,利用正交分析得到了催化剂制备的最佳实验条件:焙烧温度为500℃,焙烧时间为2.5 h,镧掺杂量为0.5%,该条件下制备的镧掺杂二氧化钛光催化剂处理莠去津废水的催化降解效率可达80%以上。 相似文献
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Macroporous FCC catalyst and macroporous HDS catalyst were prepared using polystyrene spheres as template. The size of the macropores can be tailored by controlling the size of template. The BET surface area and the pore volume of the macroporous catalysts are larger than those of catalysts prepared without template, and the more template used, the larger the surface area and pore volume obtained. When the same amount of template was used, the smaller diameter template produced a catalyst with larger surface area and pore volume. The increments in surface area and pore volume of the catalysts were greater than those predicted from the geometry of the template, indicating particle template could inhibit the shrinkage of the catalyst during drying. When used as heavy oil FCC catalysts and heavy oil HDS catalyst, the prepared macroporous catalysts are much more active than catalysts prepared without the template. 相似文献
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以自然沉积的聚苯乙烯(PS)胶体晶体为模板,分别以正硅酸乙酯(TEOS)的醇盐溶液和溶胶溶液为前驱体对PS模板进行填充,通过煅烧除去模板,得到了三维有序大孔(3DOM) SiO2材料.由SEM照片观察发现,当以TEOS的醇盐溶液为前驱体时,获得的3DOM SiO2结构不易控制,缺陷较多.而以TEOS的溶胶溶液为前驱体时获得的3DOM SiO2结构良好,孔径大小均匀,排列整齐,可以看成是PS模板的逆复制,说明前驱体溶液的选择对3DOMSiO2材料的微观结构有显著的影响.XRD分析显示,制备的3DOM SiO2孔壁为无定形结构. 相似文献
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造粒模板是切粒系统的主要部位之一,造粒模板内部包括加热通道与物料通道,通道内部流动介质分别为导热油和聚乙烯。探究在同等条件下,导热油进口速度分别为0.01、0.05、0.1 m/s的情况下物料挤出速度与造粒带温度分布的均匀性。应用SolidWorks软件对造粒模板进行三维建模,采用ANSYS软件对聚合物与导热油的流动与传热进行数值模拟,获得了造粒模板的温度分布与流体流场分布。结果表明,导热油的进口速度对造粒模板温度场的影响明显,导热油进口速度在0.01、0.05、0.1 m/s 3个条件下,物料的挤出速度变化不大,造粒带的温差分别为14.08、7.14和5.39 ℃。在导热油进口速度为0.1 m/s时,造粒带温度分布最均匀。 相似文献
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A highly selective imprinted film was produced from a formic acid solution of nylon. Amino acids were used as template molecules and spin cast films typically of the order of 1 μm, but as thin as 500 nm, were routinely prepared. The films were shown to be specific to the identity and chirality of the template amino acid, and were shown to be effective after as many as five cycles of template extraction and reintroduction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3611–3615, 2002 相似文献
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用直流腐蚀的方法,在HF溶液中用p型单晶硅[p-Si(100)]制备了单孔φ3 μm×2 μm、总孔容积0.0224 mm3的多孔硅母模。用浸入置换的方法在多孔硅上沉积了Ag、Au、Pd、Pt的催化晶粒层。用化学镀的方法在多孔硅母模上沉积了一层厚约15 μm的Ni镀层,然后用电镀的方法增厚至200 μm,并从多孔硅上超声剥离,得到镍阳模。形貌显示,催化晶粒层只在多孔硅的棱边上沉积,不在孔洞中生长,多孔硅在保持多孔形状的同时,负载了一层贵金属催化剂,可以用来制备集成催化功能的微反应器。镍阳模与多孔硅的结合面是一层带环隙的岛状颗粒,可以用作微换热器。用此方法可以用简单、价廉的工艺制备适用性较广的热集成的贵金属催化微反应器元件。 相似文献
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《Microporous and mesoporous materials》2007,98(1-3):330-338
The effect of cationic template on the adsorption of aromatic compounds in MCM-41 was investigated in the present work. Various MCM-41 samples were prepared through controlling template removal during the synthesis of MCM-41 materials in which cationic surfactant was used as a template. The properties of synthesized samples were characterized with X-ray diffraction (XRD), nitrogen adsorption, FTIR and thermogravimetric analysis etc. The adsorption equilibriums of toluene, cumene and water on MCM-41 samples were measured using a digital microbalance. Compared with parent MCM-41 with template removed completely (denoted as MCM-41), the samples with template partially removed (denoted as C-MCM-41) exhibited moderate adsorption capacity for aromatic compounds. However, the adsorption equilibrium of water showed that the hydrophobicity on the surface of C-MCM-41 was significantly enhanced. The combination of moderate adsorption capacity for aromatics and hydrophobicity for water is desirable for the applications including removal of VOCs. It was found that the adsorption behaviors of aromatic compounds and water in various MCM-41 samples were governed by both porosity and cationic spots generated by cationic templates; and the former played a more important role than the latter when aromatics were adsorbed. The porosity and cation density of the MCM-41 material can be tailored by controlling the removal of the cationic template from the pore structure. The influence of template extraction methods on the structure and adsorption properties of MCM-41 materials has also been addressed. 相似文献
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采用二次阳极氧化工艺制备了高度规则排列的多孔氧化铝(PAA)模板,并利用模板法与溶胶-凝胶法结合的模板组装技术制备了氧化钛纳米线阵列,得到了直径在50 nm左右,线间距约为50 nm的纳米线阵列.研究了模板组装过程不同压力条件对溶胶向模板孔洞中填充度的影响,发现在一定的负压条件下,有利于PAA孔中气体的排出,得到高的溶胶填充度,进而制备出高质量的纳米线阵列.分别通过SEM及XRD技术表征了PAA模板及纳米线的形貌及相结构.SEM观察发现纳米线彼此平行,表面光洁,不存在龟裂,纳米线的长度和直径与所使用模板的厚度和直径一致,表明纳米线的生长受控于模板;XRD分析表明模板为单一的θ-Al2O3晶型,纳米线为锐钛矿型TiO2. 相似文献