【作者】 顾晓娜；

【导师】 陈锋；

【作者基本信息】 华东理工大学 ， 应用化学， 2011， 硕士

【摘要】 本论文包括两方面的内容,重点对铈离子改性的钛酸盐的制备及其光催化活性进行了研究。第一部分采用离子交换和煅烧处理复合方法制备了铈离子交换的钛酸盐。考察了离子交换溶液pH值、铈离子的插入量和煅烧处理对钛酸盐的影响。铈离子交换后,钛酸盐层间距减小,晶胞体积收缩,主体层状结构发生断裂。铈离子以[CeO]2+的形式存在于钛酸盐层间。煅烧处理后,层间Ce3+含量略微增加；另外,钛酸盐的主体层内部晶格结构发生重组,使其在离子交换反应中出现的主体层结构断裂减少乃至慢慢消失。采用上述复合方法制备的钛酸盐的光催化活性明显高于离子交换法制备的钛酸盐。在影响钛酸盐光催化活性的因素中,由于离子交换反应导致的钛酸盐主体层状结构的断裂效应相比铈离子价态的变化有更重要的作用。论文第二部分分别采用固相合成法和共聚络合法制备了铈离子掺杂的钛酸盐,Na4Ce3Ti6O20。所制备样品的光催化活性都明显低于第一部分中制备的钛酸盐。铈离子的存在形式是影响钛酸盐光催化活性的非常重要的因素,铈离子插入到钛酸盐层间比掺杂到钛酸盐主体层状结构中更有利于光生电子和空穴的分离。另外,样品的比表面积也是影响钛酸盐光催化活性的一个重要因素。更多还原

【Abstract】 This thesis mainly includes two aspects, both of which study the preparation and photocatalytic performance of the Ce-modified layered titanate (CeTO).The first part is the preparation of CeTO via a hybrid method based on ion-exchange and thermal treatment. The impacts of pH value, cerium ion intercalation dosage and calcinaton treatment on the products were studied. The interlayer shrinkage, lattice cell contraction and lattice dislocations occur during the ion-exchange. The intercalated cerium ions were suggested as [CeO]2+ in the titanate, while thermal treatment seems promoting the recovering of some Ce3+ions. In addition, calcination treatment reduces the lattice dislocations from the ion-exchange via lattice restructuration, so the photocatalytic reactivities were enhanced after calcinaton treatment. It is lattice dislocation more than the chemical valence of cerium plays an important role in determining the photocatalytic reactivity of CeTOs.The second part of the thesis is the preparation of cerium doped sodium titanates with solid-state reaction and polymeric complex method. The as-prepared products are identified as a hexatitanate-like phase of Na4Ce3Ti6O20.The photocatalytic reactivities of the products are significantly lower than that of CeTOs prepared in the first part. It seems that the existence form of cerium ion in the titanates plays a very important role in determining the photocatalytic reactivity of Ce-modified titanate. Cerium ion intercalated into the interlayer but not doped into the host layer seems better for the separation of photogenerated electrons and holes. The BET surface area of the samples is another important factor which can influence photocatalytic reactivity.更多还原