原位合成CoPc/SnO2的键合特性及可见光光催化活性

报道了酞菁钴(CoPc)分子原位自组装于纳米SnO2颗粒表面, CoPc大环分子与SnO2表面形成Co—O轴向相互作用, 测定了原位合成方法(标记为i)制备的CoPc/SnO2(i)与浸渍法(标记为d)制备CoPc/SnO2(d)间的结合特性, 并进行了可见光光催化表征及CoPc敏化机理探讨. 结果表明, 在结合位点数相当的情况下, CoPc/SnO2(i)结合常数比CoPc/SnO2(d)的高两个数量级, 前者的光催化效率亦比后者高32.5%(光照150 min), 且CoPc/SnO2(i)光催化稳定性较高(重复十次循环使用). 其CoPc敏化SnO2的机理为, 由于敏化剂与半导体之间存在的强相互作用, 不仅增强了光生电荷在CoPc的LUMO与SnO2半导体导带间的导入效率及光生电荷对的分离效率, 而且提高了敏化剂的负载稳定性与循环光催化效率的持续性.

Binding Characteristics of CoPc/SnO2 by In-situ Process and Photocatalytic Activity under Visible Light Irradiation

Cobalt phthalocyanine (CoPc) was synthesized and self-assembled on the surface of nanoscale tin dioxide (SnO2) by in-situ process, marked as i, and Co-O interaction was verified to conjugate axially between macromolecule (CoPc) and SnO2 in CoPc/SnO2(i). The results indicated that the binding constant of CoPc/SnO2(i) was two-order higher than that of CoPc/SnO2(d) synthesized by dipping process, marked as d, while the numbers of binding sites were comparable in both samples. The degradation rate in the photocatalytic activity of CoPc/SnO2(i) was 32.5% higher than that of CoPc/SnO2(d) under visible-light irradiation for 150 min due to the effective electron separation and energy injection from LUMO of CoPc to conduction band of SnO2 for CoPc/SnO2(i) based on the strong interaction between CoPc and SnO2. The degradation recyclability of CoPc/SnO2(i) retained 48.8% in 10 times under the same circular photocatalytic process.