PO43-掺杂Bi2O2CO3/Bi0的制备及其可见光催化性能

构建氧空位以及附着金属单质Bi(Bi⁰)是增强半导体材料光吸收性能、促进半导体光生载流子分离的有效方法。通过简单的共沉淀法及氢气热还原成功制备了PO₄^3-掺杂Bi₂O₂CO₃附着Bi⁰(Bi-P-BOC)的可见光催化剂，并对其在可见光下催化降解氧氟沙星(OFX)的性能及机理进行了研究。材料表征结果表明BOC随着PO₄^3-的均匀掺杂，可见光吸收能力增强，表面缺陷增多，比表面积增大。而随着氢气热还原，BOC表面形成 Bi⁰的同时也原位构建了大量的氧空位。可见光催化性能测试表明，Bi-P-BOC可以在180 min内降解约85%的OFX，降解速率为0.013 0 min^-1，是BOC降解速率的8倍。Bi-P-BOC光催化降解机理表明其具有更好的可见光吸收能力，Bi⁰以及氧空位的存在促进了光生载流子的分离，h+是其光催化降解过程中的主要的活性氧物种(ROS)，此外，¹O₂和·O₂^-也对降解有一定贡献。

Preparation and visible-light photocatalytic properties of PO43- doped Bi2O2CO3/Bi0

In this work, metal Bi(Bi⁰) decorated PO₄^3- doped Bi₂O₂CO₃ (BOC) nanocomposites (Bi-P-BOC) was successfully prepared through a simple co-precipitation method with a subsequent thermal reduction process, and its photocatalytic degradation mechanism of ofloxacin (OFX) under visible light irradiation was studied. The result demonstrated that PO₄^3- was uniformly doped in BOC, which showed increased visible light response range, increased surface defects, and enlarged specific surface area. Through the thermal reduction process, a number of oxygen vacancies were produced as well as the loading of Bi⁰ on the surface of BOC. Bi-P-BOC was able to degrade 85% of the OFX in 180 min under visible light with a degradation rate of 0.013 0 min^-1, which was about eight times than pristine BOC and about two times than P-BOC-6. The UV-visible diffuse reflectance spectroscopy spectrum showed the enhanced visible light absorption attribute to the surface plasmon resonance effect of Bi⁰. The improved separation of the photoinduced electron and hole pairs were confirmed by the photoluminescence spectrum. Thus, the enhanced photocatalysis performance of Bi-P-BOC may mainly be benefited from its increased visible light response range and improved separation of the photoinduced electron and hole pairs. Furthermore, h⁺ was detected to be the main reactive oxygen species (ROS) species for the degradation of OFX in this system, ¹O₂ and ·O₂^- also made contributions to the degradation.