氮杂石墨烯/硫化铋近红外光催化降解氨氮

Photocatalytic degradation of ammonia-nitrogen via N-doped graphene/bismuth sulfide catalyst under near-infrared light irradiation

采用水热法一步合成氮杂石墨烯/硫化铋(NG/Bi2S3)复合材料,以X射线粉末衍射、拉曼光谱、扫描电子显微镜、紫外可见近红外漫反射光谱等对催化剂进行了表征。以此复合材料为催化剂,在近红外光辐射下研究了氨氮催化降解。结果表明,当氨氮初始浓度为100.0 mg·L^-1、溶液的pH值为9.0、催化剂量为0.050 g、NG负载量为3 wt%、近红外光照射10 h时,氨氮的降解率达到91.4%。相同条件下,Bi2S3对氨氮的降解率只有65.5%。动力学研究表明,氨氮降解遵循一级反应动力学规律,其表观速率常数为0.1240 h^-1。7次循环氨氮的降解率仍然大于85.5%,显示出NG/Bi2S3复合催化剂非常稳定。

The N-doped graphene/bismuth sulfide(NG/Bi2S3)composite was synthesized by hydrothermal method.The structure and properties of the catalyst were characterized by X-ray powder diffraction,Raman spectroscopy,scanning electron microscopy and UV-visible near-infrared diffuse reflectance spectroscopy.The degradation of ammonia-N was studied using 0.050 g NG/Bi2S3 as photocatalyst under near-infrared light irradiation.The results show that the degradation ratio of ammonia-N reaches 91.4%in 100.0 mg·L^-1 ammonia-N solution with pH 9.0 under near-infrared light irradiation for 10 h.Under similar conditions,the degradation ratio of ammonia-N is only 65.5%when pure Bi2S3 is used as the photocatalyst.Kinetic studies show that the ammonia-N degradation follows the first-order reaction kinetics,and the average value of the apparent rate constant is 0.1240 h^-1.Catalyst stability studies show that the degradation ratio of ammonia nitrogen in 7 runs is still greater than 85.5%,which indicates that the NG/Bi2S3 composite catalyst is very stable.