Abstract:

Using Bi(NO₃)₃·5H₂O and Co(CH₃COO)₂·4H₂O as raw materials, heterostructure composite semiconductor photocatalyst Co₃O₄-Bi₂O₂CO₃ was prepared by chemical precipitation-hydrothermal method. The physical and chemical properties of the catalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse-reflectance spectrum (DRS) and photoluminescence (PL) spectra. The results showed that the introduction of Co₃O₄ does not change the phase structure of Bi₂O₂CO₃, but promoted the visible light absorption capacity of Bi₂O₂CO₃, increased the number of oxygen adsorbed species on the surface of Bi₂O₂CO₃, and inhibited the recombination of photogenerated carriers. The photocatalytic decolorization experiment of Rhodamine B (RhB) by the composite photocatalyst shows that the introduction of Co₃O₄ can significantly improve the photocatalytic decolorization ability of Bi₂O₂CO₃ catalyst. In particular, the Co₃O₄-Bi₂O₂CO₃ sample with the doping amount of 0.6% has the best photocatalytic performance. The RhB dye removal rate can reach 97% under the irradiation of visible light at room temperature for 30min. This study provides a simple and feasible technical route for the preparation of composite photocatalysts. The novel Co₃O₄-Bi₂O₂CO₃ hetero-structured photocatalysts may have potential applications in environmental purifications.

Key words: Bi₂O₂CO₃, Co₃O₄, catalyst, photocatalysis, degradation

摘要：

以Bi(NO₃)₃·5H₂O、Co(CH₃COO)₂·4H₂O为原料，采用化学沉淀-水热法制备了Co₃O₄-Bi₂O₂CO₃异质结构复合半导体光催化剂，并通过X射线衍射仪（XRD）、扫描电镜（SEM）、X射线光电子能谱（XPS）、紫外可见漫反射光谱（DRS）、荧光光谱（PL）等手段对所合成的复合型催化剂进行了理化性能表征。研究结果表明：引入Co₃O₄没有改变Bi₂O₂CO₃物相结构，但促进了Bi₂O₂CO₃ 对可见光的吸收能力，提高了Bi₂O₂CO₃表面吸附氧物种的数量，抑制了光生载流子复合。复合光催化剂对罗丹明B（RhB）的光催化脱色实验显示引入Co₃O₄能够明显提高Bi₂O₂CO₃催化剂的光催化脱色能力。尤其是Co₃O₄引入量为0.6%的Co₃O₄-Bi₂O₂CO₃样品对罗丹明B染料的光催化脱色率可达到97%（模拟日光照射30min）。本文为复合型光催化剂制备提供了简单易行的技术路线，制备的新型半导体复合光催化剂Co₃O₄-Bi₂O₂CO₃在环境净化方面表现出了较好的应用前景。

关键词: Bi₂O₂CO₃, Co₃O₄, 催化剂, 光催化, 降解