燃烧法制备二氧化钛催化剂的条件对其可见光催化性能的影响

Titania catalysts were synthesized by a solution combustion method （SCM）. Photodegradation of 4-chlorophenol （4-CP） using the synthesized catalysts was studied under both visible light （λ≥420nm） and sunlight irradiation. The effect of preparation conditions on photocatalytic activities of the synthesized catalysts was investigated. The optimal photocatalytic activity of the catalyst （denoted as A1 ） was obtained under the following synthesis conditions： ignition temperature of 350~C, fuel ratio （ φ） of 1 and calcination time of lh. The degradation and mineralization ratio of 4-CP were 78.2% and 53.7% respectively under visible light irradiation for 3h using catalyst A1. And the catalyst A1 also showed high photocatalytic activity under sunlight irradiation.     

镧、碳共掺杂TiO2的制备及其可见光催化性能

为了更有效地利用太阳能，以钛酸丁酯为前驱体，硝酸镧和四丁基氢氧化铵为掺杂离子给体，通过改进的溶胶-凝胶法，成功制备了纯TiO₂和不同掺杂浓度的镧、碳掺杂和共掺杂TiO₂光催化剂.表征结果显示，共掺杂催化剂为锐钛矿型，具有较高的比表面积，感光范围拓展到可见光区.分别以甲基橙、罗丹明B和4-氯酚为降解物，氙灯、太阳光和自然光为光源，进行催化剂的光催化降解实验，结果表明，共掺杂催化剂活性高于未掺杂和单掺杂催化剂.降解结果显示，当共掺杂催化剂含0.5% La³⁺(摩尔比)、焙烧温度在500℃时具有最高的光催化降解效率.共掺杂TiO₂具备较高的可见光催化活性原因可能是碳掺杂降低了TiO₂禁带宽度，而镧掺杂同时维持了体系的电荷平衡.