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All total 5 Articles be found
All total 5 Articles be foundSynthesis of nitrogen-doped ZnO by sol-gel method: Characterization and its application on visible photocatalytic degradation of 2,4-D and picloram herbicides
Macías-Sánchez,Hinojosa-Reyes,Caballero-Quintero,De La Cruz,Ruiz-Ruiz,Hernández-Ramírez,Guzmán-Mar
, p. 536 - 542 (2015/03/14)
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. This journal is
Degradation of benomyl, picloram, and dicamba in a conical apparatus by zero-valent iron powder
Ghauch, Antoine
, p. 1109 - 1117 (2007/10/03)
Reduction of some pesticides (benomyl, picloram, and dicamba) was studied in an aerobic batch conical pilot system to investigate the disappearance of these pesticides on contact with iron powder (20 g/l, 325-mesh). Aqueous buffered solutions of the compounds were added to the system followed by zero-valent iron powder (ZVIP), and the decline in the pesticide concentrations was monitored over time. HPLC analyses show a complete disappearance of picloram (1.20 mg/l) after 20 min of reaction. Benomyl (1.00 mg/l) and dicamba (1.25 mg/l) disappear after 25 and 40 min, respectively. The t50 values ranged from 3 to 5.5 min, and were about slightly less than the t1/2 values reported when the log of the relative HPLC peak area was plotted versus time, where the relative peak area was calculated by dividing the measured peak area by the initial peak area. Pathways for the degradation of the studied pesticides by ZVIP are proposed.
Substituent Effects on the Isomer Ratios in the Rearrangement of Some 2- and 4-Nitraminopyridines
Deady, Leslie W.,Korytsky, Olga L.,Rowe, Jeffrey E.
, p. 2025 - 2034 (2007/10/02)
The preparation, and rearrangement in 92percent sulfuric acid, of 4-X-2-nitramino- (1), 2-X-4-nitramino- (2), and 6-X-2-nitramino-pyridines (3) is reported (X=H,Me,MeO,Br,Cl,CO2H).The product isomer ratios can be explained by differential electronic stabilization of the appropriate ? complexes for aromatic nitration and steric effects seem relatively unimportant.Deuteration had no effect on the product distribution
