摘要：

半导体光催化技术是解决环境污染问题的有效策略。TiO₂是目前应用最广泛的半导体之一。然而，较宽的带隙和载流子的快速复合制约了它的实际应用价值，通过构建异质结可以有效解决上述问题。通过酞菁钴（CoPc）原位复合得到了S型的TiO₂/CoPc异质结，二者匹配的能带结构使光生载流子得到有效分离。同时，金属Co离子中心可以活化过一硫酸盐（PMS）。光催化实验结果表明，TiO₂/CoPc异质结+PMS在可见光下照射60 min可实现72%的盐酸四环素（TC）降解。与TiO₂+PMS相比，反应速率提升了11倍，这是因为光生电子改善了Co²⁺/Co³⁺的循环，异质结中载流子的高效分离和Co²⁺/Co³⁺循环起协同效应，实现了对TC的高效降解。

关键词: TiO₂/CoPc, S型异质结, 过一硫酸盐, 光催化降解

Abstract:

Semiconductor photocatalysis is an effective strategy for solving environmental pollution problems. TiO₂ is one of the most widely used semiconductors. However, the wider bandgap and the fast complexation of carriers constrain its practical application. The above problems can be solved effectively by constructing heterojunctions. Herein, S-type TiO₂/CoPc heterojunction was obtained by in situ complexation with cobalt phthalocyanine(CoPc),and the matched energy band structure of the two enabled the effective separation of photogenerated carriers. Meanwhile, the metal Co ion centre could activate peroxymonosulfate(PMS). The results of photocatalytic experiments showed that the TiO₂/CoPc heterojunction+PMS could achieve 72% degradation of tetracycline hydrochloride(TC) by irradiating under visible light for 60 min. Compared with TiO₂+PMS, the reaction rate was increased by 11 times. The excellent photocatalytic performance may be attributed to the improved Co²⁺/Co³⁺ cycling by photogenerated electrons, and the synergistic effect of efficient carrier separation and Co²⁺/Co³⁺ cycling in the heterojunction achieved the efficient degradation of TC.

Key words: TiO₂/CoPc, S-scheme heterojunction, peroxymonosulfate, photocatalytic degradation

中图分类号: 

• X703.1