95-76-1Relevant articles and documents
Lanthanum ion doped nano TiO2 encapsulated in zeozyme and impregnated in a polystyrene film as a photocatalyst for the degradation of diuron in an aquatic ecosystem
Saranya,Sathiyanarayanan,Maheswari
, p. 110970 - 110975 (2016)
The occurrence of chlorinated herbicide diuron in water bodies is considered serious pollution and a major health hazard to flora, fauna and mankind. In the present investigation, we studied the photocatalytic degradation of diuron in an aquatic ecosystem using lanthanum ion doped nano TiO2 (Lnp) encapsulated in NaY zeolite pores (1 : 10) and impregnated in polystyrene film (ZLT). The hydrophobic nature of the polystyrene support resulted in an efficient and highly recoverable heterogeneous system. Catalyst characterization was carried out by FT-IR, XRD, DRS-UV, fluorescence, BET, SEM-EDAX and XPS. BET results revealed the successful loading of lanthanum ion doped TiO2 (Lnp) inside the NaY zeolite pores via a decrease in surface area for the zeolite encapsulated Lnp (ZLnp) as compared to NaY zeolite alone. DRS UV supported the impregnation of ZLnp in the polystyrene films; the bathochromic shift (Δλ) was 4 nm and the hypochromic shift decreased in intensity 10 fold. The photocatalytic reaction was carried out at a concentration of 20 mg L-1 of diuron, with 0.01 M H2O2 and a catalytic amount of 500 mg L-1 ZLT under unstirred conditions. Degradation of diuron by ZLT reached 40% after 2 hours. Noteworthy features are the good results under optimized conditions and that the same film models were used successfully in the presence of zebra fish (Danio rerio). The present investigation also demonstrated successful re-use of the photocatalytic film six times without any appreciable loss in catalytic activity. From the abovementioned results, it was proven that ZLT is an efficient and ecofriendly catalyst.
Kinetics of the chemical degradation of diuron.
Salvestrini, Stefano,Di Cerbo, Paola,Capasso, Sante
, p. 69 - 73 (2002)
The influence of pH and buffer concentration on the chemical degradation of diuron in water has been analysed over a wide temperature range. The process irreversibly gives 3,4-dichloroaniline as the only product containing the phenyl ring. H+, OH- and phosphate buffer are efficient catalysts of the reaction. The rate constant first increases rapidly at low buffer concentrations and then gradually levels off at higher ones. At 40 degrees C and high phosphate concentration (>0.01 M), or in the extreme pH regions, the half-life is approximately 4 months and the activation energy is 127 +/- 2 kJmol(-1).
Minimization of Back-Electron Transfer Enables the Elusive sp3 C?H Functionalization of Secondary Anilines
Zhao, Huaibo,Leonori, Daniele
supporting information, p. 7669 - 7674 (2021/03/08)
Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N-Dialkyl-derivatives enable radical generation α to the N-atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back-electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence of an exogenous alkylamine. This approach synergistically aids aniline SET oxidation and then accelerates the following deprotonation. In this way, the generation of α-anilinoalkyl radicals is now possible and these species can be used in a general sense to achieve divergent sp3 C?H functionalization.
Synthesis of CoFe2O4@Pd/Activated carbon nanocomposite as a recoverable catalyst for the reduction of nitroarenes in water
Hamadi, Hosein,Kazeminezhad, Iraj,Mohammadian, Sara
, (2021/07/06)
Efficient reduction of nitro compounds into amines is an important industrial transformation. So, it is a great deal to design new catalysts for efficient reduction of the nitro compounds especially in water. In this work, a new magnetic Pd/activated carbon nanocomposite (CoFe2O4@Pd/AC) was synthesized via metal-impregnation-pyrolysis method. The CoFe2O4@Pd/AC was fully characterized by FT-IR, PXRD, FESEM, TEM, VSM, EDX-mapping and BET techniques. The results showed that CoFe2O4@Pd/AC is a highly reactive and easily recoverable magnetic catalyst for the reduction of the nitro compounds by using NaBH4 in water. For instance, aniline was obtained in high yield (99%) after 75 ?min at 25 ?C by using just 6 ?mg of the catalyst. In addition, CoFe2O4@Pd/AC was recovered by a simple magnetic decantation and it exhibits stable activity and remains intact during the catalytic process with no significant loss in activity (8 cycles).