介孔复合微纳结构CaTi2O5的可控制备及光催化性能研究

The photocatalytic degradation is a new wastewater treatment technology with industrial application prospects, and nanomaterials with the controlled size and morphology have attracted considerable attention due to its unique micro-nano structure, dimension and high surface and their potential applicationgs in catalyst control techniques. For the shortcomings of catalyst preparation process complex, high cost and reclamation difficulty, this project would put forward CaTi2O5 mesoporous and micro-nano structure as a novel photocatalyst, and the controllable preparation of CaTi2O5 micro-nano structure by solvothermal method. Relationships between the different morphologies and photocatalytic properties of CaTi2O5 would be studied, forming a kind of high efficient preparation technology of photocatalytic materials. Using CaTi2O5 and CaTi2O4(OH)2/C3N4 composite extended the visible light range of CaTi2O5 to improve light energy utilization efficiency and photocatalytic properties, so that it has more extensive practical application prospect. And the photocatalytic reaction of oxygen atomic on the degradation of dye exchange mechanism is discussed, and the model of the reaction mechanism of photocatalytic oxidation will be set up. It will provide the important scientific basis for the preparation of new photocatalyst and regulation of the photocatalytic reaction.

光催化降解是一项新兴的、具有工业应用前途的废水处理技术，可控尺寸和形貌的纳米/微米材料因具有独特的微纳结构、维度尺寸和高比表面积，在光催化领域具有广阔的应用前景而备受关注。针对微纳结构的可控合成难和传统纳米粉末光催化剂易团聚等问题，本项目提出介孔复合微纳结构CaTi2O5作为新型光催化剂，采用简易的溶剂热法控制CaTi2O5的介孔微纳结构。研究CaTi2O5不同形貌与光催化性能的关系，形成一种效率更高的光催化材料的制备技术。并用CaTi2O5与CaTi2O4(OH)2、C3N4复合，使光催化剂吸收的光波波长红移至可见光范围，提高光能利用率和光催化活性，使其具有更广泛的实际应用前景。并对其降解染料的光催化反应氧原子交换机理进行探讨，建立光氧化反应机理模型。为今后制备新型光催化剂和调控光催化反应提供重要的科学依据。

光催化降解是一项新兴的、具有工业应用前途的废水处理技术，可控尺寸和形貌的纳米/微米材料因具有独特的微纳结构、维度尺寸和高比表面积，在光催化领域具有广阔的应用前景而备受关注。针对微纳结构的可控合成难和传统纳米粉末光催化剂易团聚等问题，本项目提出介孔复合微纳结构CaTi2O5作为新型光催化剂，采用简易的溶剂热法控制CaTi2O5的介孔微纳结构。研究CaTi2O5不同形貌与光催化性能关系的科学问题，形成一种效率更高的光催化材料的制备技术。并用CaTi2O5与C3N4复合，使光催化剂吸收的光波波长红移至可见光范围，提高光能利用率和光催化活性，使其具有更广泛的实际应用前景。并对其降解染料的光催化反应氧原子交换机理进行探讨，建立光氧化反应机理模型。为今后制备新型光催化剂和调控光催化反应提供重要的科学依据。研究发现：（1）以氯化钙为钙源，Ca/Ti摩尔比例为1/1.05，水热温度180℃，水热时间36h， pH值为3.2~5.2，所制备的由粒径为30-50nm的纳米颗粒所组成的CaTi2O5微纳结构在紫外-可见光照射下具有优于市售P25的光催化活性，该粉体可重复回收并便于储存，并且工艺路线简单。（2）C3N4/CaTi2O5可见光光催化剂的关键制备工艺为：选择C3N4/CaTi2O5摩尔比为1:1，固相复合温度300℃，保温时间1h。（3）在可见光照射下，C3N4和CaTi2O5吸收光子的能量高于它们相应的禁带宽度，由于激发电子到导带，而在价带中留下空穴。尽管内在电场阻碍C3N4中的电子从价带转移到CaTi2O5中的导带，但是却促进了C3N4价带中的空穴向CaTi2O5中的导带转移，这显著地减少光生电子和空穴的复合，从而复合样品的光催化效率大大增加。上述研究结果为实现新型CaTi2O5光催化剂材料替代现有光催化剂材料奠定科学和实验基础。