Macías-Sánchez J J, Hinojosa-Reyes L, Caballero-Quintero A, de la Cruz W, Ruiz-Ruiz E, Hernández-Ramírez A, Guzmán-Mar J L
Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León C.P. 66451, Mexico.
Photochem Photobiol Sci. 2015 Mar;14(3):536-42. doi: 10.1039/c4pp00273c.
In this work, nitrogen-doped ZnO material was synthesized by the sol-gel method using zinc acetate as the precursor and urea as the nitrogen source (15, 20, 25 and 30% wt.). For comparative purposes, bare ZnO was also prepared. The influence of N doping on structural, morphological, optical and photocatalytic properties was investigated. The synthesized catalysts were characterized by XRD, SEM-EDS, diffuse reflectance UV-Vis spectroscopy, BET and XPS analysis. The photocatalytic activity of N-doped ZnO catalysts was evaluated during the degradation of a mixture of herbicides (2,4-D and picloram) under visible radiation ≥400 nm. The photo-absorption wavelength range of the N-doped ZnO samples was shifted to longer wavelength compared to those of the unmodified ZnO. Among different amounts of dopant agent, the 30% N-doped ZnO material showed higher visible-light activity compared with pure ZnO. Several degradation by-products were identified by using HPLC and ESI-MS/MS. The enhancement of visible photocatalytic activity of the N-doped ZnO semiconductor could be mainly due to their capability in reducing the electron-hole pair recombination.
在本工作中，以醋酸锌为前驱体、尿素为氮源（质量分数为15%、20%、25%和30%），通过溶胶-凝胶法合成了氮掺杂的ZnO材料。为作比较，还制备了纯ZnO。研究了氮掺杂对结构、形貌、光学和光催化性能的影响。采用X射线衍射（XRD）、扫描电子显微镜-能谱仪（SEM-EDS）、漫反射紫外-可见光谱、比表面积分析仪（BET）和X射线光电子能谱（XPS）分析对合成的催化剂进行了表征。在≥400 nm可见光辐射下，对氮掺杂ZnO催化剂在降解除草剂（2,4-二氯苯氧乙酸和毒莠定）混合物过程中的光催化活性进行了评估。与未改性的ZnO相比，氮掺杂ZnO样品的光吸收波长范围向更长波长移动。在不同掺杂剂用量中，30%氮掺杂的ZnO材料与纯ZnO相比表现出更高的可见光活性。通过高效液相色谱（HPLC）和电喷雾电离串联质谱（ESI-MS/MS）鉴定了几种降解副产物。氮掺杂ZnO半导体可见光催化活性的增强主要归因于其减少电子-空穴对复合的能力。
