二氧化钛-聚合物纳米复合膜的制备与光致耗氧行为

Preparation of Titanium Dioxide-Polymer Nanocomposite Films and its Photocatalytic Property of Oxygen Consumption

合成了一种新型二氧化钛-聚合物纳米复合膜,用于封闭体系中光致好氧研究。以钛酸异丙酯为原料,利用凝胶-水热法制备了TiO2纳米晶粒。将商品级纳米TiO2与凝胶-水热法得到的纳米TiO2分别采用层层涂覆与混合涂膜法与聚合物复合,制备固态TiO2-聚合物纳米复合膜。提出了复合膜的结构,考察了其光稳定性和其在封闭体系中光致耗氧行为,建立了光致耗氧的动力学模型。结果表明:利用光催化原理,复合膜可消耗封闭体系中的氧气;光致耗氧反应可用Langmuir-Hinshelwood气-固相催化反应动力学模型来描述。其动力学表达式符合拟一级反应动力学。

TiO2-polymer nanocomposite film was prepared as a new kind of photocatalyst for light-driven oxygen consumption in a closed environment. Nanocrystalline TiO2 was prepared at first via gel-hydrothermal method, then the TiO2-polymer nanocomposite films, in which PVC or PEG was introduced, were prepared through two different kinds of method. The one was that the nanometer TiO2 was loaded on the substrates at first and then the polymer was coated on the nanometer TiO2 surface layer by layer, and the other one was that polymer was blended with nanometer TiO2 firstly and then the mixture was coated on substrates. The probable structure of the TiO2-polymer nanocomposite film was proposed, and its photo-stability was monitored by a UV-visible spectrophotometer. In addition, light-driven oxygen consumption on TiO2-polymer nanocomposite film was investigated in a closed environment monitored by an oxygen measurement controller, and the kinetics of deoxygenation was discussed. It concludes that oxygen could be consumed in a closed environment based on photocatalysis principle, and the kinetics of deoxygenation could be described by Langmuir-Hinshelwood equation, which is in accord with the form of a modified first-order reaction.