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Showing papers on "Nitrobenzene published in 2016"


Journal ArticleDOI
TL;DR: Interestingly, luminescent study indicated that 1 exhibits high sensitivity to electron-deficient nitrobenzene explosives via fluorescence quenching, and the material displays efficient, reversible adsorption of radioactive I2 in vapor and in solution.
Abstract: A porous luminescent zinc(II) metal–organic framework (MOF) with a NbO net [Zn2(tptc)(apy)2–x(H2O)x]·H2O (1) (where x ≈ 1, apy = aminopyridine, H4tptc = terphenyl-3,3″,5,5″-tetracarboxylic acid), constructed using paddlewheel [Zn2(COO)4] clusters and π-electron-rich terphenyl-tetracarboxylic acid, has been solvothermally synthesized and characterized. Interestingly, the material displays efficient, reversible adsorption of radioactive I2 in vapor and in solution (up to 216 wt %). The strong affinity for I2 is mainly due to it having large porosity, a conjugated π-electron aromatic system, halogen bonds, and electron-donating aminos. Furthermore, luminescent study indicated that 1 exhibits high sensitivity to electron-deficient nitrobenzene explosives via fluorescence quenching.

157 citations


Journal ArticleDOI
TL;DR: Using cadmium sulfide quantum dots as visible-light photocatalysts for the reduction of nitrobenzene to aniline through six sequential photoinduced, proton-coupled electron transfers suggests, but does not prove, that electron transfer, not proton transfer, is rate-limiting for these reactions.
Abstract: This paper describes the use of cadmium sulfide quantum dots (CdS QDs) as visible-light photocatalysts for the reduction of nitrobenzene to aniline through six sequential photoinduced, proton-coupled electron transfers. At pH 3.6–4.3, the internal quantum yield of photons-to-reducing electrons is 37.1% over 54 h of illumination, with no apparent decrease in catalyst activity. Monitoring of the QD exciton by transient absorption reveals that, for each step in the catalytic cycle, the sacrificial reductant, 3-mercaptopropionic acid, scavenges the excitonic hole in ∼5 ps to form QD•–; electron transfer to nitrobenzene or the intermediates nitrosobenzene and phenylhydroxylamine then occurs on the nanosecond time scale. The rate constants for the single-electron transfer reactions are correlated with the driving forces for the corresponding proton-coupled electron transfers. This result suggests, but does not prove, that electron transfer, not proton transfer, is rate-limiting for these reactions. Nuclear magn...

140 citations


Journal ArticleDOI
TL;DR: The luminescence explorations demonstrated that 1-Eu exhibits high quenching efficiency and low detection limit for sensing nitrobenzene and Cr2O72-.
Abstract: Two new three-dimensional isostructural lanthanide metal–organic frameworks (Ln(III)-MOFs), [LnL(H2O)3]·3H2O·0.75DMF (1-Ln; Ln = Dy(III) and Eu(III) ions, H3L = biphenyl-3′-nitro-3,4′,5-tricarboxylic acid, DMF = N,N′-dimethylformamide), were synthesized and characterized. The appearance of temperature-dependent out-of-phase (χ″M) signal reveals that complex 1-Dy displays slow magnetic relaxation behavior with the energy barrier (ΔUeff) of 57 K and a pre-exponential factor (τ0) of 3.89 × 10–8 s at 1200 Oe direct current field. The luminescence explorations demonstrated that 1-Eu exhibits high quenching efficiency and low detection limit for sensing nitrobenzene and Cr2O72–. Meanwhile, the fluorescence intensity of the quenched 1-Eu samples will be resumed after washing with DMF or water, indicating that 1-Eu may be used as a highly selective and recyclable luminescence sensing material for sensing nitrobenzene and Cr2O72– anion.

132 citations


Journal ArticleDOI
TL;DR: A more practical non-Pd cathodic electrocatalyst could be prepared and applied for electrocatalytic reduction of refractory pollutants in water and wastewater, and extend the promising applications of TiO2 in the fields of environmental science.
Abstract: TiO2 is a typical semiconductor and has been extensively used as an effective photocatalyst for environmental pollution control. But it could not be used as an electrochemical reductive catalyst because of its low electric conductivity and electrocatalytic activity. In this work, however, we demonstrate that TiO2 can act as an excellent cathodic electrocatalyst when its crystal shape, exposed facet and oxygen-stoichiometry are finely tailored by the local geometric and electronic structures. The defect-engineered TiO2–x single crystals dominantly exposed by high-energy {001} facets exhibits a high cathodic activity and great stability for electrochemical reduction of nitrobenzene, a typical refractory pollutant with high toxicity in environment. The single crystalline structure, the high-energy {001} facet and the defective oxygen vacancy of the defect-engineered TiO2–x single crystals are found to be mainly responsible for their cathodic superiority. With the findings in this work, a more practical non-P...

101 citations


Journal ArticleDOI
TL;DR: An electrochemical sensing platform which comprises gold nanoparticles (Au NPs) incorporated zinc based metal-organic framework (MOF-5) is developed for the sensitive determination of nitrite and nitrobenzene as mentioned in this paper.

94 citations


Journal ArticleDOI
TL;DR: In this paper, electron-deficient ruthenium nanoparticles supported on Ru fulleride nanospheres allow the successive and chemoselective hydrogenation of nitrobenzene to aniline and then to cyclohexylamine.
Abstract: Electron-deficient ruthenium nanoparticles supported on Ru fulleride nanospheres allow the successive and chemoselective hydrogenation of nitrobenzene to aniline and then to cyclohexylamine. The catalysts were prepared in a straightforward manner by decomposition under dihydrogen of [Ru(COD)(COT)] in the presence of C60. The nitrobenzene hydrogenation reaction is solvent sensitive and proceeds more quickly in methanol than in other alcohols. The same behavior, i.e. a two-step successive hydrogenation, has been observed for several substituted nitroarenes. Density functional theory calculations suggest that the observed chemoselectivity is mainly governed by the presence of surface hydrides on the electron-deficient Ru nanoparticles. At the threshold value of 1.5 H per Ru surface atom, the formation of aniline is favored due to the net preference of the NO2 coordination.

90 citations


Journal ArticleDOI
Hongtao Duan1, Yong Liu1, Xiaohong Yin1, Jianfei Bai1, Jing Qi1 
TL;DR: In this paper, Schwertmannite was used as a heterogeneous Fenton-like catalyst for nitrobenzene degradation in a closed batch system and the results showed that removal efficiency was significantly enhanced in the presence of schwartmannite and the catalyst retained almost its high catalytic activity after 5 consecutive runs.

83 citations


Journal ArticleDOI
TL;DR: In this article, the authors used density functional theory (DFT) with the inclusion of van der Waals interaction to study the reaction mechanism in the nitrobenzene reduction reaction over the Pt(1.1) model catalyst and found that double H-induced dissociation of N-O bond was the preferential path for the activation of nitro group, having a much lower reaction barrier than that of the direct dissociation and single H-induction paths.

83 citations


Journal ArticleDOI
TL;DR: In this paper, a new metal-organic framework having the formula (NH2(CH3)2)[Zn2(OAc)(L)]·0.5DMF (H4L = 2,5-di(3′,5′-dicarboxylphenyl)pyridine) (GDMU-3) has been synthesized and characterized.
Abstract: A new metal–organic framework having the formula (NH2(CH3)2)[Zn2(OAc)(L)]·0.5DMF (H4L = 2,5-di(3′,5′-dicarboxylphenyl)pyridine) (GDMU-3) has been synthesized and characterized. The net of GDMU-3 is uninodal and is closely related to the lvt net, which has the same Schlafli symbol of 42·84. GDMU-3 displays selective properties for the detection of nitrobenzene and Fe3+ ions. Remarkably, GDMU-3 exhibits an excellent capability to adsorb methylene blue with high selectivity. The present work indicates that GDMU-3 could be a potential candidate for developing novel luminescence sensors for the selective sensing of nitrobenzene which can be deployed for explosives, Fe3+ and organic dyes.

81 citations


Journal ArticleDOI
TL;DR: The results show that the Bi2MoO6/TiO2 heterostructures exhibit excellent photocatalytic performance with maximum phenol and nitrobenzene degradation rates and corresponding mineralization rates of 66% and 61% in 300min under visible light irradiation, respectively.

80 citations


Journal ArticleDOI
TL;DR: In this paper, the real active sites of Co3O4 were revealed through a combination of XRD, XPS, HRTEM, EELS and poisoning experiments with sulfur-containing compounds.

Journal ArticleDOI
TL;DR: Mechanistic considerations based on product formation indicate that addition to the aromatic ring is the preferential reaction in the case of aniline, p-chloroaniline and p-nitroaniline which can terminate in bimolecular reactions with other compounds such as the determined o-hydroxyaniline by yielding the detected 2-amino-5-anilino-benzochinon-Anil.

Journal ArticleDOI
TL;DR: In this article, the performance of the prepared Fe/Cu bimetallic particles with different theoretical copper mass loadings were characterized by SEM, EDS, BET and XRD, and the effect of theoretical Cu mass loading and other operating parameters (such as initial pH, initial nitrobenzene concentration, the Fe/cu dosage and the reaction temperature) under oxic conditions (DO < 65mg/L) were investigated.

Journal ArticleDOI
TL;DR: The present work indicates that this metal-organic framework could be a prospective candidate for developing novel luminescence sensors for the selective sensing of nitrobenzene, which can be used as a precursor for explosives.
Abstract: A new ZnII metal-organic framework, [Zn6 (L)3 (DMA)4 ]⋅5 DMA (H4 L=[1,1':3',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid, DMA=dimethylacetamide), has been synthesized and characterized. The structure contains a three-dimensional 3,4,4,6-connected net with (4.62 )2 (66 )(66 )(42 .610 .83 ) topology and displays selective detection of nitrobenzene, CrO42- and Fe3+ ions. The present work thus indicates that this metal-organic framework could be a prospective candidate for developing novel luminescence sensors for the selective sensing of nitrobenzene, which can be used as a precursor for explosives. Furthermore, the photoluminescent properties of this material in different solvents and with various analytes were investigated and corroborated by theoretical calculations. The results were in good agreement with the experimental solvent-dependent luminescence behavior.

Journal ArticleDOI
Hao Feng1, Xun Zhu1, Rong Chen1, Qiang Liao1, Jian Liu1, Lin Li1 
TL;DR: In this paper, a gas-liquid-solid microreactor with the polydopamine functionalized surface coated by highly active palladium nanocatalysts using the electroless deposition was successfully developed for hydrogenation of nitrobenzene.

Journal ArticleDOI
TL;DR: In this paper, the role of cyclodextrins and other saccharide additives in the mechanosynthesis of gold nanoparticles and their use as catalysts in the reduction of substituted nitrobenzene derivatives into their corresponding aniline products was explored.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the kinetics and mechanism of reduction of nitrobenzene using novel silver-poly(N-isopropylacrylamide-co-allylacetic acid) hybrid microgels as catalyst.

Journal ArticleDOI
TL;DR: In this paper, surface silylation of MCM-41 with trimethylchlorosilane was conducted to improve the adsorption of nitrobenzene from aqueous solution.

Journal ArticleDOI
21 Mar 2016-Analyst
TL;DR: The PAA-AgNP modified GC electrode showed promising potential as an electrochemical sensor for nitrobenzene and exhibited minimal interference effects on structurally-similar nitroaromatic compounds and metal species.
Abstract: A novel electrochemical sensing platform for nitrobenzene has been developed using silver nanoparticles (AgNPs) embedded in the poly(amic) acid (PAA) polymer matrix (PAA–AgNPs). PAA was synthesized via the polycondensation reaction of para-phenylenediamine and benzene-1,2,4,5-tetracarboxylic dianhydride. PAA–AgNP nanocomposites were synthesized by the in situ reduction of a silver precursor by the polymer at room temperature in a one-step approach without using an extraneous reducing or capping agent. The composite was subsequently characterized in solution and as a thin film. The X-ray diffraction technique revealed the crystalline nature of the PAA films with the embedded AgNPs. Unlike conventional polymers, the synthesized PAA membrane exhibits significant UV/Vis spectroscopic response. The sequestered nanoparticles also show the characteristic surface plasmon resonance (SPR) peaks confirming the presence of AgNPs. Integrated charge areas were 4.826 mC and 2.176 C for PAA/GC and PAA–AgNPs/GC respectively. The charge at the PAA–AgNP/GC electrode is 451 times greater than that at the PAA/GC electrode suggesting that the AgNP composite exhibits higher electroactivity. When tested as a sensor for nitrobenzene, the PAA–AgNP modified GC electrode showed promising potential as an electrochemical sensor. The electrochemical sensors exhibit a wide linear dynamic range (10–600 μM) with a correlation coefficient of 0.9735, a detection limit of 1.68 μM and a sensitivity of 7.88 μA μM−1. The sensor also exhibited minimal interference effects on structurally-similar nitroaromatic compounds and metal species such as 4-nitroaniline (4-NA), 2-nitrophenol (2-NP), dinitrobenzene (DNB), Pb2+ and Cd2+.

Journal ArticleDOI
TL;DR: In this article, a novel tetradentate ligand combining hard O-donor and soft N-donors in the same molecule, N,N′-diethyl-N, N′-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen), was developed in our laboratory aiming at the group separation of actinides from lanthanides.

Journal ArticleDOI
TL;DR: In this article, the authors investigated transition-metal-loaded silicon nanoparticles for the photocatalytic reduction of nitro-arene derivatives in the presence of formic acid under visible light irradiation.
Abstract: We investigated transition-metal-loaded silicon nanoparticles for the photocatalytic reduction of nitroarene derivatives in the presence of formic acid under visible light irradiation. Formic acid assumes the role of both a hydrogen source and a sacrificial reagent for the introduction of electrons into the generated holes of semiconductors. As such, in the presence of formic acid, photocatalytic reactions smoothly proceed under mild conditions without gaseous hydrogen. In particular, palladium-loaded silicon (Pd/Si) was the most suitable catalyst for the conversion of nitrobenzene to aniline, compared to Pt/Si, Ru/Si, and Pd/C.

Journal ArticleDOI
TL;DR: In this paper, three different poly(N-isopropylacrylamide-co-acrylic acid) [p(NIPAM-AA)] microgel samples were prepared using a precipitation polymerization method by varying the concentration of NIPAM and AA in aqueous medium.
Abstract: Abstract Three different poly(N-isopropylacrylamide-co-acrylic acid) [p(NIPAM-AA)] microgel samples were prepared using a precipitation polymerization method by varying the concentration of NIPAM and AA in aqueous medium. The microgels were used as microreactors to fabricate Ag nanoparticles (NPs) by in situ a reduction method. Fourier transform infrared (FTIR) and UV-visible spectroscopy were used to characterize the pure and hybrid microgels. The hybrid microgels with different AA content were used as catalysts for reduction of nitrobenzene (NB) into aniline. The progress of the reaction was monitored by a UV-visible spectrophotometer. The results show that the value of the apparent rate constant for catalytic reduction of NB decreases from 0.431 min-1 to 0.227 min-1 by increasing AA content from 3 mol% to 7 mol%, respectively. Decrease in apparent rate constant with increase of AA content can be attributed to an increase in hydrophilicity with increase of AA contents of the microgels. The increase in induction period with increase of AA contents indicates that diffusion of NB towards the catalytic surface becomes difficult due to an increase of hydrophilicity.

Journal ArticleDOI
Ming Liu1, Xun Zhu1, Rong Chen1, Qiang Liao1, Hao Feng1, Lin Li1 
TL;DR: In this article, a catalytic membrane microreactor (CMMR) with the catalytic membranes formed by coating the catalysts on a thin PDMS film modified by dopamine was developed in this study, which not only eliminated the issues in the conventional gas-liquid-solid reactors but also provided a large surface area-to-volume ratio to enhance the mass transport.

Journal ArticleDOI
TL;DR: The luminescence properties of the Cd-MOF showed that it could be an effective sensor to the organic nitrobenzene molecule via a strong quenching effect, and also to the inorganic Tb(III) ion by a strong green emission effect.
Abstract: A Cd(II)-based metal-organic framework, [Cd2(DPDC)2(BTB)]∞ (Cd-MOF, DPDC = 2,2'-diphenyldicarboxylate and BTB = 1,4-bis(1,2,4-triazol-1-yl)butane) was successfully constructed via a hydrothermal reaction. Structural analysis shows that the synthesized Cd-MOF is a three-dimensional (3D) architecture crystallized in the hexagonal system with a chiral space group P61. Powder X-ray diffraction experiments and thermogravimetric analysis reveal that the constructed Cd-MOF has a high chemical and thermal stability. A study of additional mechanical properties indicates that it exhibits a moderate stiffness with the average values of Young's modulus (E) and H as 11.3(2) and 0.9(7) GPa, respectively. The luminescence properties of the Cd-MOF were further studied. The result shows that it could be an effective sensor to the organic nitrobenzene molecule via a strong quenching effect, and also to the inorganic Tb(III) ion by a strong green emission effect. Moreover, when loading bimetal ions (Eu(III) and Tb(III) into the Cd-MOF/methanol suspension, tunable visible luminescence can also be achieved by carefully adjusting the excitation wavelengths.

Journal ArticleDOI
TL;DR: The Voronoi deformation density analysis has been applied to aniline and nitrobenzene to obtain an insight into the charge rearrangements due to the substituent and it was shown that it is the repulsive interaction between the πHOMO of the phenyl radical and the NH2 radical that is responsible for pushing up the τHOMM of anilines and therefore activating this π orbital of the Phenyl ring towards electrophilic substitution.
Abstract: The substituent effect of the amino and nitro groups on the electronic system of benzene has been investigated quantum chemically using quantitative Kohn–Sham molecular orbital theory and a corresponding energy decomposition analysis (EDA). The directionality of electrophilic substitution in aniline can accurately be explained with the amount of contribution of the 2pz orbitals on the unsubstituted carbon atoms to the highest occupied π orbital. For nitrobenzene, the molecular π orbitals cannot explain the regioselectivity of electrophilic substitution as there are two almost degenerate π orbitals with nearly the same 2pz contributions on the unsubstituted carbon atoms. The Voronoi deformation density analysis has been applied to aniline and nitrobenzene to obtain an insight into the charge rearrangements due to the substituent. This analysis method identified the orbitals involved in the C–N bond formation of the π system as the cause for the π charge accumulation at the ortho and para positions in the case of the NH2 group and the largest charge depletion at these same positions for the NO2 substituent. Furthermore, we showed that it is the repulsive interaction between the πHOMO of the phenyl radical and the πHOMO of the NH2 radical that is responsible for pushing up the πHOMO of aniline and therefore activating this π orbital of the phenyl ring towards electrophilic substitution.

Journal ArticleDOI
TL;DR: In this paper, a stable nonanuclear rare earth carboxylate cluster based metal-organic framework (DMA) 2[Y9(μ3-OH)8(μ2-HO)3BTB6]n·(solv)x (gea-MOF-1) is proposed to detect nitrobenzene and aniline.
Abstract: A stable nonanuclear rare earth carboxylate cluster based metal–organic framework, (DMA)2[Y9(μ3-OH)8(μ2-OH)3BTB6]n·(solv)x (gea-MOF-1) (DMA = dimethylamine cation and BTB = 1,3,5-benzene(tris)benzoate) can act as a fluorescent sensor for highly sensitive and selective detection of nitrobenzene and aniline through fluorescence quenching. More importantly, the detection limit of nitrobenzene is on the 5–60 ppm scale.

Journal ArticleDOI
TL;DR: Catalytic reduction of nitrobenzene to aniline studies reveals that BaTiO3 synthesized by microwave is very active and showed 99.3% nitro Benzene conversion with 98.2% anilines yield.
Abstract: In the present study synthesis of BaTi1-xCrxO3 nanocatalysts (x = 0.0 ≤ x ≤ 0.05) by conventional oxalate and microwave assisted hydrothermal synthesis methods was carried out to investigate the effect of synthesis methods on the physicochemical and catalytic properties of nanocatalysts. These catalysts were thoroughly characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 physisortion, and total acidity by pyridine adsorption method. Their catalytic performance was evaluated for the reduction of nitrobenzene using hydrazine hydrate as the hydrogen source. Structural parameters refined by Rietveld analysis using XRD powder data indicate that BaTi1-xCrxO3 conventional catalysts were crystallized in the tetragonal BaTiO3 structure with space group P4mm, and microwave catalysts crystallized in pure cubic BaTiO3 structure with space group Pm3m. TEM analysis of the catalysts reveal spherical morphology of the particles, and these are uniformly dispersed in microwave catalysts whereas agglomeration of the particles was observed in conventional catalysts. Particle size of the microwave catalysts is found to be 20-35 nm compared to conventional catalysts (30-48 nm). XPS studies reveal that Cr is present in the 3+ and 6+ mixed valence state in all the catalysts. Microwave synthesized catalysts showed a 4-10-fold increase in surface area and pore volume compared to conventional catalysts. Acidity of the BaTiO3 catalysts improved with Cr dopant in the catalysts, and this could be due to an increase in the number of Lewis acid sites with an increase in Cr content of all the catalysts. Catalytic reduction of nitrobenzene to aniline studies reveals that BaTiO3 synthesized by microwave is very active and showed 99.3% nitrobenzene conversion with 98.2% aniline yield. The presence of Cr in the catalysts facilitates a faster reduction reaction in all the catalysts, and its effect is particularly notable in conventional synthesized catalysts.

Journal ArticleDOI
Peng Zhou1, Jing Zhang1, Jilong Liu1, Yongli Zhang1, Juan Liang1, Ya Liu1, Bei Liu1, Wei Zhang1 
TL;DR: In this article, zero valent copper (nZVC) particles were employed as an activator for persulfate (PS) to degrade organic contaminants, and the degradation rate of BA increased gradually with an increase of nZVC dosage.
Abstract: Recently, persulfate (PS) has fascinated practitioners of water treatment as a promising oxidant for in situ chemical oxidation. In this study, zero valent copper (nZVC) particles were employed as an activator for PS to degrade organic contaminants. Benzoic acid (BA) was almost completely degraded in 25 min, and the nZVC/PS process exhibited a ubiquitous oxidizing capacity on various organic contaminants (including acid orange 7, nitrobenzene, dimethyl phthalate, diethylstilbestrol, bisphenol A, and 2,4-dichlorophenol). The mechanism investigation showed that PS can accelerate the corrosion of nZVC to release Cu+ in acidic aqueous conditions, and the reactive radicals were generated through the further activation of PS by intermediate Cu+ via a Fenton-like reaction. Both sulfate radical (SO4−˙) and hydroxyl radical (˙OH) were considered as the primary reactive radicals in the nZVC/PS process due to the intense inhibition with the addition of methanol (MA) and tert-butyl alcohol (TBA). Moreover, the degradation rate of BA increased gradually with an increase of nZVC dosage, and the decrease of the initial pH range from 5.4 to 2.0.

Journal ArticleDOI
TL;DR: In this paper, a magnetic C-Fe3O4-Pd catalyst was used for the transfer hydrogenation of nitro compounds by the use of NaBH4 as the hydrogen donor at room temperature.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the photocatalytic efficiency of single-walled carbon nanotubes (SWCNT) composites with respect to bacteriophage MS2 inactivation, nitrobenzene degradation, and redox species production under UV-A irradiation.