515-74-2Relevant articles and documents
Photodegradation of methyl orange catalyzed by nanoscale zerovalent iron particles supported on natural zeolite
Naderpour, Hamidreza,Noroozifar, Meissam,Khorasani-Motlagh, Mozhgan
, p. 471 - 479 (2013)
A nanoscale catalyst Fe0(FeNPs) supported on the natrolite zeolite nanoparticles (NANPs) is successfully synthesized and characterized by FT-IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM) and thermogravimetric-differential thermal analysis (TG-DTA). The photodegradation of methyl orange (MO) is studied in aqueous suspension containing the catalyst under UV irradiation and H2O2. The effect of various reaction parameters such as initial dye concentration, irradiation time, pH, H2O2 concentration and catalyst dosage on the decolorization of methyl orange is investigated. The degradation study reveals that the reactivity of the catalysts is in order of: photo-NANPs-FeNPs-H 2O2 > photo-NANPs-H2O2 > photo-NANPs-FeNPs > photo-H2O2 > NANPs-FeNPs-H 2O2. The results show that methyl orange can be effectively decolorized by NANPs-FeNPs via the pseudo-first-order kinetic model.
Enhanced decolorization of methyl orange using zero-valent copper nanoparticles under assistance of hydrodynamic cavitation
Li, Pan,Song, Yuan,Wang, Shuai,Tao, Zheng,Yu, Shuili,Liu, Yanan
, p. 132 - 138 (2015)
The rate of reduction reactions of zero-valent metal nanoparticles is restricted by their agglomeration. Hydrodynamic cavitation was used to overcome the disadvantage in this study. Experiments for decolorization of methyl orange azo dye by zero-valent copper nanoparticles were carried out in aqueous solution with and without hydrodynamic cavitation. The results showed that hydrodynamic cavitation greatly accelerated the decolorization rate of methyl orange. The size of nanoparticles was decreased after hydrodynamic cavitation treatment. The effects of important operating parameters such as discharge pressure, initial solution pH, and copper nanoparticle concentration on the degradation rates were studied. It was observed that there was an optimum discharge pressure to get best decolorization performance. Lower solution pH were favorable for the decolorization. The pseudo-first-order kinetic constant for the degradation of methyl orange increased linearly with the copper dose. UV-vis spectroscopic and Fourier transform infrared (FT-IR) analyses confirmed that many degradation intermediates were formed. The results indicated hydroxyl radicals played a key role in the decolorization process. Therefore, the enhancement of decolorization by hydrodynamic cavitation could due to the deagglomeration of nanoparticles as well as the oxidation by the in situ generated hydroxyl radicals. These findings greatly increase the potential of the Cu0/hydrodynamic cavitation technique for use in the field of treatment of wastewater containing hazardous materials.
Cu/CuxS-Embedded N,S-Doped Porous Carbon Derived in Situ from a MOF Designed for Efficient Catalysis
Wang, Dongsheng,Fan, Mingyue,He, Tingyu,Zeng, Fanming,Hu, Xiaoli,Li, Chun,Su, Zhongmin
supporting information, p. 11468 - 11476 (2021/06/14)
The reasonable design of the precursor of a carbon-based nanocatalyst is an important pathway to improve catalytic performance. In this study, a simple solvothermal method was used to synthesize [Cu(TPT)(2,5-tdc)] ? 2H2O (Cu-MOF), which contains N and S atoms, in one step. Further in-situ carbonization of the Cu-MOF as the precursor was used to synthesize Cu/CuxS-embedded N,S-doped porous carbon (Cu/CuxS/NSC) composites. The catalytic activities of the prepared Cu/CuxS/NSC were investigated through catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The results show that the designed Cu/CuxS/NSC has exceptional catalytic activity and recycling stability, with a reaction rate constant of 0.0256 s?1, and the conversion rate still exceeds 90 % after 15 cycles. Meanwhile, the efficient catalytic reduction of dyes (CR, MO, MB and RhB) confirmed its versatility. Finally, the active sites of the Cu/CuxS/NSC catalysts were analyzed, and a possible multicomponent synergistic catalytic mechanism was proposed.
Acid properties of organosiliceous hybrid materials based on pendant (fluoro)aryl-sulfonic groups through a spectroscopic study with probe molecules
Erigoni, Andrea,Paul, Geo,Meazza, Marta,Hernández-Soto, María Consuelo,Miletto, Ivana,Rios, Ramon,Segarra, Candela,Marchese, Leonardo,Raja, Robert,Rey, Fernando,Gianotti, Enrica,Díaz, Urbano
, p. 6308 - 6317 (2019/11/20)
Two different heterogeneous catalysts carrying aryl-sulfonic moieties, in which the aromatic ring was either fluorinated or not, were successfully synthesized. The multi-step synthetic approaches implemented involved the synthesis of the silyl-derivative, template-free one-pot co-condensation (at low temperature and neutral pH) and tethering reaction. A multi-technique approach was implemented to characterize the hybrid organic-inorganic catalysts involving TGA, N2 physisorption analysis, FTIR spectroscopy, and ss MAS NMR (1H, 13C, 29Si) spectroscopy. Specifically, the acidity of the organosiliceous hybrid materials was studied through the adsorption of probe molecules (i.e. CO at 77 K and NH3 and TMPO at room temperature) and a combination of FTIR and ss MAS NMR spectroscopy. The catalytic activity of the two hybrids was tested in the acetal formation reaction between benzaldehyde and ethylene glycol. Preliminary results indicated superior performances for the fluoro-aryl-sulfonic acid, compared to the non-fluorinated sample. The findings hereby reported open new avenues for the design of heterogeneous sulfonic acids with superior reactivity in acid-catalyzed reactions. Moreover, through the implementation of spectroscopic studies, using probe molecules, it was possible to investigate in detail the acidic properties of hybrid organosiliceous materials.
