title: Synthesis of nitrogen-doped ZnO by sol-gel method: characterization and its application on visible photocatalytic degradation of 2,4-D and picloram herbicides.
abstract: 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.
authors.affiliation: Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León C.P. 66451, Mexico. jorge.guzmanmr@uanl.edu.mx.
authors.forename: J J
authors.initials: JJ
authors.lastname: Macías-Sánchez
authors.forename: L
authors.initials: L
authors.lastname: Hinojosa-Reyes
authors.forename: A
authors.initials: A
authors.lastname: Caballero-Quintero
authors.forename: W
authors.initials: W
authors.lastname: de la Cruz
authors.forename: E
authors.initials: E
authors.lastname: Ruiz-Ruiz
authors.forename: A
authors.initials: A
authors.lastname: Hernández-Ramírez
authors.forename: J L
authors.initials: JL
authors.lastname: Guzmán-Mar
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000737:chemistry*; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D006540:Herbicides / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D055668:Photochemical Processes; D010846:Picloram / Q000737:chemistry*; D015034:Zinc Oxide / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D006540:Herbicides; D015084:2,4-Dichlorophenoxyacetic Acid; D009584:Nitrogen; D010846:Picloram; D015034:Zinc Oxide