CdS/Nb_(2)O_(5)异质结材料的制备、表征及光催化降解环丙沙星研究

Synthesis,Characterization,and Photocatalytic Degradation of Ciprofloxacin Using CdS/Nb_(2)O_(5) Heterojunction Materials

采用水热法制备了CdS/Nb_(2)O_(5)纳米复合材料,利用X-射线衍射光谱(XRD)、透射电镜(TEM)、红外光谱(FT-IR)、X-射线光电子能谱(XPS)和紫外-可见漫反射(UV-Vis DRS)对制备的材料进行表征。通过可见光下降解环丙沙星评价材料的光催化活性。结果表明,制备的CdS/Nb_(2)O_(5)纳米复合材料由CdS纳米颗粒分散于Nb_(2)O_(5)纳米笼表面,二者形成紧密的Ⅱ型异质结;CdS的引入增强了Nb_(2)O_(5)的可见光吸收性能,同时提高了光生载流子的分离效率;当CdS的含量为15%时,CdS/Nb_(2)O_(5)可在60 min实现环丙沙星的高效降解,其反应速率常数是CdS的7.5倍,Nb_(2)O_(5)的20倍,空穴是该降解反应的主要活性物种,研究结果为抗生素废水的高效治理提供了一条新思路。

CdS/Nb_(2)O_(5) nanocomposites were prepared using a hydrothermal method,and the prepared materials were characterized using X-ray diffraction(XRD),transmission electron microscopy(TEM),Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS).The photocatalytic activity of the material was evaluated by the degradation of ciprofloxacin under visible light eradiation.The results showed that the prepared CdS/Nb_(2)O_(5) nanocomposites consisted of dispersed CdS nanoparticles on the surface of Nb_(2)O_(5) nanocages,forming a closely packed typeⅡheterojunction.The introduction of CdS enhanced the visible light absorption of Nb_(2)O_(5) and improved the separation efficiency of photo-generated charge carriers.When the content of CdS was 15%,the CdS/Nb_(2)O_(5) achieved efficient degradation of ciprofloxacin within 60 minutes,with a reaction rate constant 7.5 times larger than that of CdS and 20 times larger than that of Nb_(2)O_(5),indicating that photo-generated holes were the main active species in the degradation reaction.This study provides a new approach for the efficient treatment of antibiotic wastewater.