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.
Preparation and catalytic properties of magnetic rectorite-chitosan-Au composites
Zhang, Rufei,Zheng, Pengwu,Ma, Xiaofei
, p. 381 - 389 (2017)
A novel composite was assembled by introducing magnetic Fe3O4nanoparticles, chitosan and Au nanoparticles (AuNPs) on rectorite (REC) surfaces. The obtained REC-Fe3O4-CTS-Au composite was characterized and used as the catalyst to remove 4-nitrophenol (4-NP) and methyl orange (MO) from water in the presence of NaBH4. The large surface of REC and the abundant hydroxyl group of chitosan on REC surface could restrain the agglomeration of AuNPs. REC-Fe3O4-CTS-Au exhibited the superiority in catalytic efficiency. At the catalyst dosage of 150?mg/L, it took only 15?min for 0.2?mM 4-NP solution to reach complete reduction, and 30?min for 1.0?mM 4-NP solution. This catalyst had the higher catalytic activity for 4-NP than MO reduction. Moreover, the catalyst could be conveniently separated and recycled from the reaction mixtures using an external magnetic field, and reused for 4-NP (or MO) reduction in fourteen cycles with retaining the original 99% (or 95%) conversion efficiency. This work indicates that REC-Fe3O4-CTS-Au can be a promising catalyst for the highly efficient degradation of organic dyes.
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(BDC) as a catalyst for rapid reduction of methyl orange: room temperature synthesis using recycled terephthalic acid
Rahmani, Alireza,Rahmani, Hossein,Zonouzi, Afsaneh
, p. 449 - 455 (2018)
Terephthalic acid was recycled from waste PET bottles with a basic hydrolysis technique and characterized with UV and FTIR spectroscopy. Copper-based metal–organic framework Cu(BDC) was synthesized at room temperature without any additive; two different temperatures were chosen to activate the obtained material. Characterization studies were performed using XRD, N2 physisorption, STEM and EDX. The obtained material was tested as a catalyst for the reduction of methyl orange with NaBH4 in aqueous solutions. Thermal activation at 160?°C proved to be mandatory for catalytic activity; although higher temperature activation did not cause significant enhancement. Rapid dye removal was monitored by continuous photometry at λmax. The results were quite satisfactory (about 85% removal in 5?min); even higher than the published results for precious metal (i.e., Au, Pt and Ag) nanoparticles. In an increased reaction scale, UV–visible spectra and mass spectrum were recorded to help elucidating the possible reaction mechanism. In addition, recycling experiment were performed in 100-ml scale without any kind of re-activation (washing or drying) to show the ability of Cu(BDC) as a stable catalyst for reductive dye removal (and probably similar reactions as well).
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.
Co/Cu bimetallic ZIF as New heterogeneous catalyst for reduction of nitroarenes and dyes
Gholinejad, Mohammad,Naghshbandi, Zhwan,Sansano, José M.
, (2020/02/04)
Nowadays one of the great challenges is to design new bimetallic catalysts with enhanced catalytic activity, selectivity and recycling properties. In this work, the preparation of new Co/Cu bimetallic Zeolitic Imidazolate Framework (Co-Cu/ZIF) as an efficient catalyst for the reduction of nitro compounds and organic dyes is described. Co-Cu/ZIF was characterized with different techniques such as SEM, TEM, XRD, XPS, TGA, FT-IR and UV–vis absorption indicating formation of entirely uniform cubic particles. Using this catalyst, structurally different aromatic nitro compounds were reduced efficiently to corresponding amines in excellent yields. Kinetic studies revealed that the reduction rates of nitrophenol isomers follow 3-NP > 4-NP > 2-NP order. The catalytic activity of Co-Cu/ZIF was further investigated in the reduction of organic dyes such as methyl orange (MO) and rhodamine B (RhB). This catalyst was recycled for at least ten runs in the reduction of 4-nitrophenol without a noticeable decrease in activity and reused catalyst was characterized.
Catalytic applications of β-cyclodextrin/palladium nanoparticle thin film obtained from oil/water interface in the reduction of toxic nitrophenol compounds and the degradation of azo dyes
Zare Asadabadi, Azam,Hoseini, S. Jafar,Bahrami, Mehrangiz,Nabavizadeh, S. Masoud
, p. 6513 - 6522 (2019/05/10)
A supramolecular catalyst of Pd/β-cyclodextrin thin film is synthesized via a facile and one-pot procedure at an oil-water interface. Macrocyclic oligosaccharides of cyclodextrins with glucose units have a wide range of applications due to their hydrophobic and chiral interior. Due to the ability of this supramolecular catalyst to form inclusion complexes with small organic molecules, the as-synthesized catalyst was applied for the reduction of toxic nitroaromatic compounds (p, o, m-nitrophenol and 4-Cl-2-nitrophenol) and the degradation of harmful azo dyes (methyl orange and bismarck brown) with considerable results. This investigation illustrates the change of the catalyst properties in the presence of molecular receptors attached to the catalyst surface.
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.
METHOD FOR PURIFICATION OF ANTIBODIES, ANTIBODY FRAGMENTS OR ENGINEERED VARIANTS THEREOF USING SPECIFIC ANTHRAQUINONE DYE-LIGAND STRUCTURES
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Page/Page column 35; 36, (2015/09/23)
The present invention relates to novel adsorbents applicable a process for the separation or purification of antibodies, antibody fragments or engineered variants thereof, which comprise anthraquinone dye ligands; corresponding purification processes; and corresponding analytical or preparative separation kits.
Fullerene-catalyzed reduction of azo derivatives in water under UV irradiation
Guo, Yong,Li, Wengang,Yan, Jingjing,Moosa, Basem,Amad, Ma'An,Werth, Charles J.,Khashab, Niveen M.
supporting information, p. 2842 - 2847 (2013/02/23)
Metal-free fullerene (C60) was found to be an effective catalyst for the reduction of azo groups in basic aqueous solution under UV irradiation in the presence of NaBH4. Use of NaBH4 by itself is not sufficient to reduce the azo dyes without the assistance of a metal catalyst such as Pd and Ag. Experimental and theoretical results suggest that C 60 catalyzes this reaction by using its vacant orbital to accept the electron in the bonding orbital of azo dyes, which leads to the activation of the N=N bond. UV irradiation increases the ability of C60 to interact with electron-donor moieties in azo dyes. Filling a vacancy: Experimental and theoretical methods have been combined to show that C60-catalyzed reductions of azo compounds form aromatic amines under UV irradiation (see scheme). The obtained results show that C60 acts as an electron acceptor to catalyze the reduction of azo compounds, and the role of UV irradiation is to increase the ability of C60 to interact with electron-donor moieties in azo compounds. Copyright
