席夫碱钴卟啉-TiO2复合光催化剂的制备及其光催化性能研究

Preparation and Photocatalytic Activity of Schiff Base Cobalt Porphyrin-TiO_2 Composites

采用Alder法合成的5-对硝基苯基-10,15,20-三苯基钴卟啉,通过浓盐酸/Sn Cl2还原得5-对氨基苯基-10,15,20-三苯基钴卟啉,再与对硝基苯甲醛反应生成席夫碱钴卟啉,以席夫碱钴卟啉为敏化剂,并与纯锐钛矿型TiO_2作用,得到相应的金属卟啉敏化TiO_2复合光催化剂XFJ-Co-TPP-TiO_2。利用红外、紫外-可见漫反射光谱、XRD和SEM对所得金属卟啉以及XFJ-CoTPP-TiO_2复合光催化剂进行了表征和分析。分析结果表明,所合成的金属卟啉均为目标化合物,金属卟啉成功负载于TiO_2表面。以亚甲基蓝和罗丹明B为模型反应物,研究XFJ-Co-TPP-TiO_2复合催化剂的可见光光催化性能,与纯TiO_2的光催化效果相比,用席夫碱钴卟啉敏化后的TiO_2对亚甲基蓝和罗丹明B的光催化效果有了明显的提高。可见光条件照射下,各种清除剂对光催化降解反应的影响表明,空穴(h+)是催化剂XFJ-Co-TPP-TiO_2-1光降解罗丹明B反应体系中的主要活性物种。

A Schiff base cobalt porphyrin, namely N-（5-p-phenyl） -10, 15, 20-triphenyl porphyrin-nitrophenyl azomethine, denoted as XFJ-Co-TPP, was prepared by chemical synthetic method. Using XFJ-Co-TPP as sensitizer, anatase TiO2 samples were impregnated with metal porphyrin to form XFJ-Co-TPP-TiO2 composite photocatalysts. The photocatalysts were characterized by FT-IR, UV-Vis DRS, XRD and SEM. The results showed that the as-synthesised Schiff base cobalt porphyrins were target compound, which were successfully depositedon the surface of TiO2. The photocatalytic activity of XFJ-Co-TPP-TiO2 composite photocatalysts was investigated throughthe photocatalysts assisted degradation of methylene blue（MB） and Rhodamine B （RhB） under visible light irradiation. It was found that XFJ-Co-TPP-TiO2 composite exhibited much higher photodegradation efficiency than the bare TiO2 catalysts. The effect of various radical scavengers on the degradation of RhB with XFJ-Co-TPP-TiO2-1 as catalyst showed thath＋ was likely to be major active specie responsible for the dye degradation under visible light.