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One-pot reductive alkylation of nitrobenzene with alcohol is an important organic synthesis reaction to form 2° amines. In the present work, we have demonstrated that Pd/SBA-15 can be an effective catalytic system for this reaction. We have designed ultra-small Pd nanoparticles supported on SBA-15 for the synthesis of secondary amine, N-ethylaniline, through one-pot reductive alkylation of nitrobenzene with ethanol under ambient conditions. Ethanol functions both as the alkylating agent and the solvent in this process. The reaction is driven by the simultaneous hydrogenation of nitrobenzene to aniline, dehydrogenation of ethanol to aldehyde, and condensation of aniline and acetaldehyde to form N-ethylaniline. The size of the Pd nanoparticles plays a decisive role in the product selectivity. The undercoordinated sites present on ultra-small Pd NPs can facilitate ethanol dehydrogenation to acetaldehyde, thereby enhancing the selectivity towards N-ethylaniline compared to larger Pd nanoparticles. We have also studied the effect of different mesoporous supports such as SBA-15, MCM-41, and KIT-6 on the N-ethylaniline selectivity and found that SBA-15 was most selective. We have demonstrated that by carefully designing the catalyst such as controlling the Pd NPs size to obtain the maximum quantity of undercoordinated sites and choosing suitable support, the aliphatic alcohols can also be used for reductive alkylation of nitrobenzene in one-pot with optimum yields of N-alkylaniline. [ABSTRACT FROM AUTHOR]

• Nitrobenzene was completely converted to aniline by using PdO/TiO 2 as catalysts with an ultra-low apparent activation energy. • Active hydrogen species were perceived as dominant species which fully came from NaBH 4. • The initial PdO nanoparticles in PdO/TiO 2 provided the adsorption sites for nitro groups. • The Pd/PdO/TiO 2 would be formed in situ by adding NaBH 4. • The Pd nanoclusters would activate NaBH 4 to generate active hydrogen species to attack the adsorbed nitro groups. The reduction of nitrobenzene to aniline is very important for both pollution control and chemical synthesis. Nevertheless, difficulties still remain in developing a catalytic system having high efficiency and selectivity for the production of aniline. Herein, it was found that PdO nanoparticles highly dispersed on TiO 2 support (PdO/TiO 2) functioned as a highly efficient catalyst for the reduction of nitrobenzene in the presence of NaBH 4. Under favorable conditions, 95% of the added nitrobenzene (1 mmol/L) was reduced within 1 min with an ultra-low apparent activation energy of 10.8 kJ/mol by using 0.5%PdO/TiO 2 as catalysts and 2 mmol/L of NaBH 4 as reductants, and the selectivity to aniline even reached up to 98%. The active hydrogen species were perceived as dominant species during the hydrogenation of nitrobenzene by the results of isotope labeling experiments and ESR spectroscopic. A mechanism was proposed as follows: PdO activates the nitro groups and leads to in-situ generation of Pd, and the generated Pd acts as the reduction sites to produce active hydrogen species. In this catalytic system, nitrobenzene prefers to be adsorbed on the PdO nanoparticles of the PdO/TiO 2 composite. Subsequently, the addition of NaBH 4 results in in-situ generation of a Pd/PdO/TiO 2 composite from the PdO/TiO 2 composite, and the Pd nanoclusters would activate NaBH 4 to generate active hydrogen species to attack the adsorbed nitro groups. This work will open up a new approach for the catalytic transfer hydrogenation of nitrobenzene to aniline in green chemistry. [Display omitted] [ABSTRACT FROM AUTHOR]

AbstractThree new terpenoid derivatives (1S,6R,7S)-hydrobenzosydowic acid (1), (1 R,6S,7S)-hydrobenzosydowic acid (2), and (7 R,10R)-11-dehydroxy-iso-10-hydroxysydowic acid (3), along with the known analogues (S)-2-(1-(4-nitrobenzoyl)pyrrolidine-2-carboxamido)benzoic acid (4) and trihydroxybutyl ester of 4-carboxydiorcinol (5) were isolated from the deep-sea-derived fungus Aspergillus sydowii DFFSCS007. Their structures were determined by spectroscopic analysis. Compound 4 with a nitrobenzene group was isolated from nature for the first time. The antibacterial activities of 1-5 and cytotoxicity of 1-3 were also evaluated. [ABSTRACT FROM AUTHOR]

A visible‐light‐promoted reduction of nitrobenzenes using formate salts as the reductant was developed. A wide range of nitrobenzenes can be converted into aniline products in a transition metal free fashion. Mechanistic studies revealed that radical species (carbon dioxide radical anion and thiol radical) are key intermediates for the transformation. We anticipate that this method will provide a valuable and green strategy for the reduction of nitrobenzenes. [ABSTRACT FROM AUTHOR]

Impregnation of phosphine‐decorated polymer‐immobilized ionic liquid with the tetrachloroaurate anion results in reduction of the gold(III) to gold(I) with concomitant oxidation of the phosphine to its oxide. In situ reduction of the resulting precursor, AuCl@O = PPh2‐PEGPIILS, generated the corresponding O = PPh2‐PEGPIIL‐stabilized AuNPs, AuNP@O = PPh2‐PEGPIILS, which is a highly active and selective catalyst for the solvent‐dependent partial reduction of nitrobenzene to N‐phenylhydroxylamine in water and azoxybenzene in ethanol. The initial TOFs are comparable to those obtained with gold nanoparticles generated by reduction of tetrachloroaurate‐impregnated phosphine oxide‐decorated polymer‐immobilized ionic liquid AuCl4@O = PPh2‐PEGPIILS, i.e., the activity and selectivity profiles do not appear to depend on whether the AuNPs are generated from Au(III) or in situ‐generated Au(I). In stark contrast, gold nanoparticles prepared by NaBH4 reduction of AuCl@PPh2‐PEGPIILS based on gold(I) confined in phosphine‐modified polymer‐immobilized ionic liquid gave markedly lower initial TOFs. The use of dimethylamine borane (DMAB) as the hydrogen donor resulted in a substantial and dramatic enhancement in activity for reductions conducted in water compared with NaBH4 and the initial TOF of 20,400 mol nitrobenzene converted mol Au−1 h−1 obtained with AuNPs generated in situ from AuCl4@O = PPh2‐PEGPIILS is among the highest to be reported for the metal nanoparticle catalyzed selective reduction of nitrobenzene to N‐phenylhydroxylamine; this is a significant improvement on existing protocols, which should enable the partial selective reduction of nitroarenes to be conducted in water with a low catalyst loading under extremely mild conditions. [ABSTRACT FROM AUTHOR]

In this work, a green and efficient method has been developed to catalyze the nitration of benzene to nitrobenzene in NO2‐O2 system by using acidic ion exchange resin as catalyst under mild (0 °C and atmospheric pressure) and solvent‐free conditions. Based on experimental screening, commercial acid ion exchange resin Amberlite FPC3500 was identified as the optimal catalyst. Under the optimized reaction conditions, 99.9 % conversion of benzene was obtained with 99.1 % selectivity of nitrobenzene. Furthermore, the catalyst is easily reusable. The results demonstrate a greener route for the production of nitrobenzene. [ABSTRACT FROM AUTHOR]

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibriums Sr2+ (aq) + 2 picrate (aq) + L (nb) ⇔ SrL2+ (nb) + 2 picrate (nb) and M2+ (aq) + SrL2+ (nb) ⇔ ML2+ (nb) + Sr2+ (aq) taking place in the two–phase water–nitrobenzene system (M2+ = Ca2+, Ba2+, Pb2+, Cu2+, Zn2+, Cd2+, Mn2+, Co2+, Ni2+, UO 2 2 + ; L = substituted calix[5]arenes; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the ML2+ complexes in nitrobenzene saturated with water were calculated. Very high stability constants of pentaethyl p-tert-butylcalix[5]arene pentaacetate ligand with Ba2+ cation has been found. [ABSTRACT FROM AUTHOR]

The Diels–Alder reaction of tetraaryl cyclopentadienones with benzo[b]thiophene-S,S-dioxides in nitrobenzene under reflux led to the formation of aryl/hetero-aryl fused phenanthrene derivatives via SO2 elimination of the intermediate dihydrodibenzothiophene-S,S-dioxides followed by 6π-electrocyclization and subsequent aromatization. The 6π-electrocyclization methodology was found to be applicable for assembling a wide variety of phenanthrene derivatives in good to moderate yields. [ABSTRACT FROM AUTHOR]

Metal‐free, strong‐base‐free, and solvent‐free synthesis of alkenyl heteroarenes through PhNO2/PhNH2 mediated direct olefination of methyl substituted N‐heteroarenes with benzylic alcohols was described. Detailed mechanistic studies indicated that in situ formed imine was the active intermediate for the olefination. PhNO2 protected benzylic alcohols from overoxidation, and PhNH2 not only acted as the coupling partner for the formation of intermediate imine, but also provides an alkaline condition for the generation of enamine salt. Gram scale reaction and the synthesis of three pharmaceutically relevant conjugated olefins were also successful using this methodology. [ABSTRACT FROM AUTHOR]

ABSTRACT Two new luminescent metal–organic frameworks (MOFs), namely, [Zn2(HL)2]n (1) and {[Cd2(HL)2(H2O)2]⋅(H2O)0.5}n (2) [H3L = 5‐((4‐(1H‐1,2,4‐triazol‐1‐yl)benzyl)amino)isophthalic acid ligand], have been solvothermally synthesized and characterized. Single‐crystal x‐ray diffraction shows that 1 exhibits a 3D framework, whereas 2 features 2D network. Furthermore, the fluorescence studies demonstrated that 1 and 2 exhibited luminescent sensing activity for nitrobenzene (NB), Fe3+ ions, and Cr2O72− anions with high selectivity, high sensitivity, and low detection limit, the corresponding detection limits of 1 were 6.40 × 10−7, 1.26 × 10−7, and 1.44 × 10−7 M, respectively, and that of 2 were 2.42 × 10−6, 3.41 × 10−7, and 2.90 × 10−7 M, respectively. 1 and 2 exhibited excellent solvent, pH, and thermal stabilities. The results suggested that both 1 and 2 can be considered as potential fluorescent sensors of NB, Fe3+ ions, and Cr2O72− anions. [ABSTRACT FROM AUTHOR]

Biomass derived carbon is considered as a promising carbon because it contains abundant channel and pore structure and is not easy to degrade. Double transition metal oxides show abundant valence states, good biocompatibility, conductivity, high stability and satisfactory catalytic properties. In addition, a large number of waste biomass such as the fruit peel could cause the waste of resources and environmental pollution. Therefore, we used waste grape skins as a carbon source for assembly with double transition metal oxides. After calcination at high temperature, N-doped biomass-derived carbon loaded with double transition metal oxide composite was formed. The waste grape skins carbon substrate with large pores and large specific surface area provides more channels for ion migration and electron transport, promotes charge transfer, and further improves the ability to reduce NB. The material shows excellent electro-catalytic activity for nitrobenzene (NB), the limit of detection (LOD) is as low as 0.143 μM, the linear response range is wide (0.47–1798.71 μM), the sensitivity is high, the reproducibility, the selectivity and the stability are good. In addition, the sensing assembled from this material has achieved a recovery rate of 97–102.6 % in testing the NB content in actual water sample. This work provides a new idea for the detection of NB, and also finds a greener and more meaningful treatment method for waste biomass. [ABSTRACT FROM AUTHOR]

The coupling of CO2 and nitrogen‐containing species nitrobenzene has become an appealing and sustainable strategy for synthesizing high‐valuable organic nitrides. However, how to realize the nitrogen bicoupled carbon bonding (C─N─C) between two CO2 and nitrobenzene has been an insurmountable challenge. Hydroxyl‐assisted cobalt single atom (CoN2O2‐(OH)2) is engineered to achieve C─N─C bonding for N, N‐dimethylaniline synthesis. The CO2 is adsorbed through hydroxyl groups, that can be reduced and C─N coupling with nitrobenzene reduction intermediate on nearby Co site, and the vacant hydroxyl group continues to adsorb next CO2, which is sequentially coupled with an intermediate of C─N coupling, achieving C─N─C bonding for synthesis N, N‐dimethylaniline. Herein, first, C─N─C bonding is achieved for green synthesis of N, N‐dimethylaniline via electrocatalytic reduction of nitrobenzene and CO2 in an aqueous phase, with a yield of 505.2 µmol L−1 h−1 on CoN2O2‐(OH)2. In situ characterizations and DFT calculations together demonstrated that the key of C─N─C bonding is that *PhNCH3 intermediate of C─N bonding continues to couple with *CO achieving C─N─C bonding to generate *PhNCOCH3 for N, N‐dimethylaniline synthesis with a much lower free energy is far easier to take place on CoN2O2‐(OH)2. This work provides inspiring new insight into the green synthesis of long‐chain organic nitrides. [ABSTRACT FROM AUTHOR]

The paper presents the results of a study of the adsorption properties chitosan (CS) spheres cross-linked with epichlorohydrin (ECH). During the study, a procedure was developed for obtaining and cross-linking of CS spheres, as well as CS-based magnetically separable composites. The adsorption capacity of CS-ECH spheres was tested by the example of aqueous solutions of Ni2+ and Cr2O72- with different concentrations. It was shown that in a batch mode the adsorption equilibrium in the case of Ni2+ was achieved in 60 min, whereas in the case of Cr2O7 2- a longer time was required (420 min or more). It was found that CS-ECH spheres can accumulate about 3 wt.% Ni2+ and up to 10 wt.% of Cr6+ ions. Magnetically separable composites (Fe3O4-CS-ECH) were found to provide higher efficiency of adsorption in comparison with CH-ECH. Moreover, the catalyst Pd/CH-ECH was synthesized and tested in hydrogenation of nitrobenzene at ambient pressure [ABSTRACT FROM AUTHOR]

We reported the gold/silver core-shell nanoparticles (Aucore@Agshell NPs) functionalized with β-cyclodextrin (β-CD) as versatile nano-agents demonstrated for human urine-based biosensing of cysteamine and catalytic conversion from nitrobenzene (NB) to aniline. First, the hybrid bimetallic nanoparticles, i.e., β-CD-Aucore@Agshell NPs, constituted a colorimetric sensing platform based on localized surface plasmons, enabling cysteamine (Cyst) to be detected in a remarkably rapid manner, i.e., within 2 min, which was greatly shortened in comparison with that of our previous report. This was due largely to use of β-CD being effectively replaceable by Cyst. The detection of Cyst was demonstrated using human urine specimens in the linear range of 25–750 nM with a limit of detection of 1.83 nM. Excellent specificity in detecting Cyst was also demonstrated against potential interfering molecules. Meanwhile, the β-CD-Aucore@Agshell NPs were demonstrated as nanocatalysts for converting NB to aniline with efficiency enhanced by more than three-fold over the pure gold nanoparticles previously reported, due to the dual functions of the structural core-shell. The demonstrated versatile features of the hybrid nanoparticles can find applications in human urine-based biosensors for Cyst detection, and in the screening of Cyst-containing drugs, while detoxicating NB for ecological protection in aqueous media. [ABSTRACT FROM AUTHOR]

AbstractA simple needle-trap device (NTD) coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine trace levels of nitrobenzenes (NBs) in workplace air. The NTD with sorbent inside the needle was employed for the quantification of nitrobenzene, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene, o-nitrochlorobenzene, m-nitrochlorobenzene, and p-nitrochlorobenzene. The optimum temperature and time for desorption of analytes were 270 °C and 4 min, and parameters such as sampling flow rate, breakthrough volume, and storage capability were also optimized. The limits of detection and quantification were in the ranges of 1.8 × 10−4–1.1 × 10−3 and 5.9 × 10−4–3.6 × 10−3 mg m−3, respectively. The developed protocol was successfully applied for the determination of NBs in vehicle repair plants where the highest detected concentration was 0.11 mg m−3. The established NTD-GC-MS generally applies to monitoring trace levels of NBs in the air. [ABSTRACT FROM AUTHOR]

As the simplest nitroaromatic compound, nitrobenzene is an interesting model system to explore the rich photochemistry of nitroaromatic compounds. Previous investigations of nitrobenzene's photochemical dynamics have probed structural and electronic properties. These investigations paint, at times, a convoluted and sometimes contradictory description of the photochemical landscape. We investigate the ultrafast dynamics of nitrobenzene triggered by photoexcitation at 267 nm for the first time using a structural probe with femtosecond time resolution. Our probe complements previous measurements of nitrobenzene's electronic structure evolution and aids in determining the photochemical dynamics with less ambiguity. We employ megaelectronvolt ultrafast electron diffraction to follow nitrobenzene's structural evolution within the first 5 ps after photoexcitation. We observe ground state recovery within 160 ± 60 fs through nonadiabatic dynamics. Based on comparisons of the experimental signal with molecular dynamics simulations, we exclude a significant population of the triplet manifold. Furthermore, we do not observe fragmentation of nitrobenzene within the investigated time window, which indicates that previously observed photofragmentation reactions take place in the vibrationally 'hot' ground state on timescales considerably beyond 5 ps. [ABSTRACT FROM AUTHOR]

In this study, we employ a catalytic system derived from a zeolitic imidazolate framework (ZIF), comprising carbon nanotube-wrapped CoFe 2 O 4 with a modified 3D cross morphology. The seamless transition between ionic valence states in CoFe 2 O 4 contributes to enhanced material conductivity, illustrating a significant synergistic coupling effect. The 3D matrix has the capacity to generate a greater number of active sites and exhibit a high surface area. The generation of nanotubes provides additional channels for electron transport, thereby improving the charge transfer efficiency and enhancing the electrochemical sensing capability of the system. The synthesized material demonstrates outstanding electrochemical sensing capabilities for nitrobenzene, exhibiting impressive sensitivity with a remarkably low limit of detection at 0.013 μM and a broad linear response range (0.06–414.9 μM), heightened sensitivity, excellent repeatability, and superior selectivity. Furthermore, the quantification of trace nitrobenzene in water samples demonstrates a recovery rate within the range of 96.0 %–102.8 %. Consequently, this material presents itself as a promising catalyst for electrochemical analysis and introduces a novel approach for detecting low concentrations of nitrobenzene. [ABSTRACT FROM AUTHOR]

Para-aminophenol (PAP) was synthesized from nitrobenzene through a two-step homogeneous acid catalyst reaction. In the first step, the intermediate of phenyl hydroxylamine was synthesized from the reduction of nitrobenzene with zinc. Next, the intermediate undergoes a Bamberger rearrangement in the presence of sulfuric acid into PAP. The PAP was purified with toluene extraction, an adsorption process with activated carbon, and crystalized by adjusting the pH solution. The reaction temperature, H2SO4 concentration, and reaction time on PAP yield were also optimized and validated. The process validation result showed that about 46.60 % PAP yield and 80 % PAP purification were obtained within the conditional process, such as a reaction temperature of 70oC, H2SO4 concentration of 1.5 M, reaction time of 150 min, and crystallization temperature of 5oC. Furthermore, the PAP product was identified with FT-IR and UPLC-MS. FT-IR spectrum showed pattern similarity with the standard of PAP, and the molar mass of the PAP synthesized measured by UPLC-MS was 109.23 g/mole, similar to PAP in the literature. [ABSTRACT FROM AUTHOR]

Two sets of co-formers, polyfluorinated arylenediamines with variable structural elements and macrocyclic ethers of different sizes, were used to study the patterns of self-assembly of co-crystals and to rank the intermolecular interactions. The co-crystallization stoichiometry was found to increase from 1 : 1 to 2 : 1 in the series trifluoro-1,3-phenylenediamine, 2,4-diaminotrifluoropyridine, and 2,4-diaminotrifluoronitrobenzene and with decreasing crown ether size due to restructuring of guest--host interactions and forming guest-guest interactions. 18-Crown-6 and 15-crown-5 ethers form the typical N--H...Ocr H-bonds connecting two Ocr atoms with one bifunctional proton donor NH2; when going to 12-crown-4, two Ocr atoms become connected with the Hamino atoms of two arylenediamine molecules. Modes of guest--guest bonding and supramolecular motifs in 2 : 1 co-crystals are determined by HB acceptors and p + π systems in arylenediamine: o-N--H...Nhet and p-N--H...F interactions form face-to-face dimers united in a chain; p-N-H...Onitro and o-N--H...Onitro contacts generate head-to-tail and head-to-side chains; π...π and X...π (X = F, O, N) electron interactions form off-set stacks. Quantum chemical calculations reveal an increase of the packing enthalpies and bonding energies with increasing arylenediamine electron affinity and crown ether size. According to MEP, BCP and NCI analyses, these effects are caused either by strengthening of the interactions due to a greater electrostatic contribution, or by multiplying bonding contacts. Quantifying the interactions allowed us to identify the key supramolecular synthons and related elements of the co-former structure, which can serve as tools in the molecular crystal design. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of a Ni-doped coral-like three-dimensional Mo 2 C nanorod via the pyrolysis of polypyrrole (PPy)-loaded NiMoO 4 ·xH 2 O nanorods for nitrobenzene (NB) detection. The incorporation of Ni species into Mo 2 C enhances dual-atom synergistic catalysis, while the inclusion of PPy as a preferred carbon source improves the composite's active area. The coral-like three-dimensional rod structure not only provides various types of sites for adsorbing reactants but also offers more channels for ion migration and electron transfer, promoting charge transfer and further enhancing its electrical conductivity. The resulting composite demonstrates a wide linear detection range (2.11–1053.61 μM), high sensitivity, low limit of detection (0.64 μM, S/N = 3), and excellent stability and anti-interference performance in NB detection. This novel composite preparation approach offers promising prospects for practical NB detection applications. [ABSTRACT FROM AUTHOR]

A novel microwave‐assisted intercalation (MAI) strategy is proposed for fast and efficient intercalation of layered MXene to prepare large‐size single‐layer MXene. After LiF‐HCl etching of Ti3AlC2, the as‐prepared multi‐layer Ti3C2Tx (M‐T) are intercalated with Li3AlF6 as an intercalator and ethylene glycol (EG) as a solvent under microwave irradiation for 5 min. Furthermore, the dispersed high‐quality large‐sized single‐layer Ti3C2Tx (S‐T) nanosheets with a thickness of 1.66 nm and a large lateral size over 20 µm are achieved with a yield of over 60% after a further ultrasonic delamination followed by electrostatic precipitation, acid washing, and calcination. In addition, Pd/S‐T composite catalyst, which is constructed with Pd nanoparticles supported on the as‐prepared S‐T nanosheets, exhibits an excellent performance for rapid and efficient selective hydrogenation of nitroarenes with H2 under a mild condition. At room temperature, full conversion of nitrobenzene and 100% aniline selectivity are achieved over Pd/S‐T catalyst in 20 min with 0.5 MPa of H2 pressure. This work provides a novel method for facile, fast, and large‐scale preparation of single‐layer MXene and develops a new approach for constructing efficient nanocatalytic systems. [ABSTRACT FROM AUTHOR]

Photocatalysis technology is green and sustainable for reduction of nitrobenzene to aniline. However, the photocatalytic activity of pure carbon nitride is limited by the high photogenerated carrier recombination rates. Carbon nitride nanosheets (CNN) were prepared by prepolymerization and high temperature calcination and cadmium sulfide (CdS) nanoparticles were in situ grown between the layers of carbon nitride for facilitating the separation and transfer of charges. As a result, the optimal composite catalyst (CdS/CNN‐2) exhibited superior photocatalytic activity with nitrobenzene reduction rate of 83 % within 60 min. This work presents an effective strategy for designing catalysts for the photocatalytic reduction of nitrobenzene. [ABSTRACT FROM AUTHOR]

As a type of diverse and structurally adjustable metal‐oxo clusters, polyoxometalates (POMs) based materials have been extensively applied as a catalysis in various valuable reactions. This review summarized recent progress in the application of POMs‐based catalysts for various carbonylation reactions including (1). Carbonylation of olefins, (2). Carbonylation of formaldehyde, (3). Carbonylation of methanol or dimethyl ether, (4). Oxidative carbonylation of methane, (5). Oxidative carbonylation of phenol and (6). Reductive carbonylation of nitrobenzene. A brief perspective on POMs‐based catalysts for the carbonylation reactions is proposed. [ABSTRACT FROM AUTHOR]

Nitrobenzene (NB) is one of the nitro-aromatic compounds that is extensively used in various chemical industries. Despite its potential applications, NB is considered to be a toxic compound that has significant hazardous effects on human health and the environment. Thus, it can be said that the NB level should be monitored to avoid its negative impacts on human health. In this vein, the electrochemical method has emerged as one of the most efficient sensing techniques for the determination of NB. The sensing performance of the electrochemical techniques depends on the electro-catalytic properties and conductivity of the electrode materials. In the past few years, various electrode materials, such as conductive metal ions, semiconducting metal oxides, metal–organic frameworks, and two-dimensional (2D) materials, have been used as the electrode material for the construction of the NB sensor. Thus, it is worth summarizing previous studies on the design and synthesis of electrode materials for the construction of the NB sensor. In this mini-review article, we summarize the previous reports on the synthesis of various advanced electrode materials, such as platinum (Pt) nanoparticles (NPs), silver (Ag) NPs, carbon dots (CDs), graphene, graphitic carbon nitride (g-C3N4), zinc stannate (ZnSnO3), cerium oxide (CeO2), zinc oxide (ZnO), and so on. Furthermore, the impacts of different electrode materials are systematically discussed for the sensing of NB. The advantages of, limitations of, and future perspectives on the construction of NB sensors are discussed. The aim of the present mini-review article is to enhance the knowledge and overall literature, working towards the construction of NB sensors. [ABSTRACT FROM AUTHOR]

This study describes a facile one-pot solvothermal method for the synthesis of heterostructured (HS) Bi2S3–TiO2 (BT) nanoparticles (NPs) and utilizes its potential for sensing the nitrobenzene (NB) as a fluorescent probe. The characterization of as-synthesized BT NPs endorses the mixed morphology with an average particle size of 14 nm and the crystallography study depicted the orthorhombic Bi2S3 and tetragonal anatase TiO2 phases. The selectivity and sensitivity of BT NPs toward NB were examined by comparing the fluorescence quenching with a few other selected organic aromatic compounds. The appreciable quenching efficiency of 97% was achieved with NB. The visual response of the BT/NB mixture was noticed under UV light (λ = 3 6 5 nm). The quenching parameters of the BT/NB system have been evaluated by modifying Stern–Volmer and double logarithmic equations. The results attribute the prevalence of dynamic quenching within the concentration range (0.4 mM to 5 mM) and beyond 5 mM, both static and dynamic quenching coexist. Further, thermodynamic studies of the BT/NB system indicate the spontaneous hydrophobic interaction. Moreover, a reliable outcome has been demonstrated in the sensing application of BT NPs in real water samples. [ABSTRACT FROM AUTHOR]

The photosensitized reaction of nitrobenzene and its derivatives, including dinitrobenzene, has been extensively investigated in an aqueous alkaline medium using Benzophenone as a sensitizer under visible light irradiation. A 100 W tungsten lamp was employed for the purpose of irradiation. The presence of the strongly electron-withdrawing NO2 group leads to polarization of the C–H bond. In this process, the triplet excited state of benzophenone initiates H+ abstraction from the polarized C–H bond of nitrobenzene (NB) and meta-dinitrobenzene (m-DNB) through exciplex formation. Proton abstraction results in the formation of free radicals for both NB and m-DNB, followed by dimerization of the free radicals. The observed rate of the reaction follows the order m-DNB > NB. However, no photochemical reaction was observed for p-dinitrobenzene (p-DNB). Various parameters such as pH, substrate concentration, sensitizer concentration, light intensity, solvent effect, and the rate of the photochemical reaction were investigated. The quantum efficiency of the product was determined using a potassium ferrioxalate actinometer. The formation of the product occurs through exciplex formation from the triplet excited state. The possible products, namely 2,2'-dinitro biphenyl and 2,2'-4,4'-tetranitro biphenyl, were confirmed using UV–visible spectrophotometry and mass spectrometry. Finally, a proposed reaction mechanism was suggested based on the experimental findings. [ABSTRACT FROM AUTHOR]

Abstract Biochar-supported ZVI have received increasing attention for their potential to remove nitrobenzene in groundwater and soil. However, the capacity of this material to enhance the biological reduction of nitrobenzene and alter microbial communities in anaerobic groundwater have not been explored. In this study, the nitrobenzene removal performance and mechanism of modified biochar-supported zerovalent iron (ZVI) composites were explored in anaerobic soil. The results showed that the 700 °C biochar composite enhanced the removal of nitrobenzene and inhibited its release from soil to the aqueous phase. NaOH-700-Fe50 had the highest removal rate of nitrobenzene, reaching 64.4%. However, the 300 °C biochar composite inhibited the removal of nitrobenzene. Microbial degradation rather than ZVI-mediated reduction was the main nitrobenzene removal pathway. The biochar composites changed the richness and diversity of microbial communities. ZVI enhanced the symbiotic relationship between microbial genera and weakened competition between soil microbial genera. In summary, the 700 °C modified biochar composite enhanced the removal of nitrobenzene by increasing microbial community richness and diversity, by upregulating functional genes, and by promoting electron transfer. Overall, the modified biochar-supported ZVI composites could be used for soil remediation, and NaOH-700-Fe50 is a promising composite material for the on-site remediation of nitrobenzene-contaminated groundwater.

This study presents an electrochemical sensor for sensitive detection of nitroaromatic compounds using a three‐dimensional (3D) porous graphene with polyoxypropylene supported reduced graphene oxide (PEA‐RGO) and embedded β‐cyclodextrins (β‐CD). First, PEA‐RGO was synthesized by the condensation reaction between graphene oxide (GO) and amino‐terminated polyoxypropylene (PEA), followed by hydrazine hydrate reduction. Then, β‐CD was embedded into the porous of the above 3D graphene to obtain PEA‐RGO/β‐CD nanohybrid. Various characterization techniques, such as microscopy imaging, infrared spectrometry, thermal analysis and electrochemical measurements, were employed to confirm the successful synthesis and unique 3D architecture structure of PEA‐RGO/β‐CD. Afterwards, the glassy carbon electrode (GCE) was modified by PEA‐RGO/β‐CD, and its electrochemical detection performances were investigated for detecting nitroaromatic compounds, including nitrobenzene (NB), 2‐nitroaniline (2‐NA), 2‐chloronitrobenzene (2‐NCB), and 2‐nitrophenol (2‐NP). The results of electrochemical measurements exhibited relative higher sensitivities (1.88 μA/μM/cm2 for NB, 2.13 μA/μM/cm2 for 2‐NA, 2.35 μA/μM/cm2 for 2‐NP, 0.83 μA/μM/cm2 for 2‐NCB, respectively) and lower limits of detection (LOD) (39.4 nM for NB, 44.6 nM for 2‐NA, 75.6 nM for 2‐NP, 69.6 nM for 2‐NCB, respectively). Additionally, the proposed sensor was also applied in detection in real samples with recovery range of 88.13%–109.52 %. The enhanced detecting performances can be attributed to the synergistic effect of the high conductivity from RGO, recognition capabilities from β‐CD, and excellent properties from 3D structure. The present work would provide a robust tool for environmental monitoring and the detection of nitroaromatic pollutants. [ABSTRACT FROM AUTHOR]

Despite that extensive efforts have been dedicated to the search for advanced catalysts to boost the electrocatalytic nitrobenzene reduction reaction (eNBRR), its progress is severely hampered by the limited understanding of the relationship between catalyst structure and its catalytic performance. Herein, this review aims to bridge such a gap by first analyzing the eNBRR pathway to present the main influential factors, such as electrolyte feature, applied potential, and catalyst structure. Then, the recent advancements in catalyst design for eNBRR are comprehensively summarized, particularly about the impacts of chemical composition, morphology, and crystal facets on regulating the local microenvironment, electron and mass transport for boosting catalytic performance. Finally, the future research of eNBRR is also proposed from the perspectives of performance enhancement, expansion of product scope, in‐depth understanding of the reaction mechanism, and acceleration of the industrialization process through the integration of upstream and downstream technologies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Commercial TiO2 nanoparticles were subjected to modification through Bi and Zn metal doping. The resulting catalysts were comprehensively characterized, and their performance was then reviewed for removal of model pollutant nitrobenzene in water. RESULTS: Amidst the synthesized catalysts, the co‐doping of Bi/Zn (0.25:0.75 wt%) demonstrated the best photocatalytic degradation activity, achieving 95% degradation within 90 min of reaction time, with 2.99 × 10−2 min−1 rate constant value. The involvement of different radicals during the degradation process was elucidated by employing appropriate radical scavengers. Furthermore, the degradation results were investigated applying the first‐order kinetic model, leading to the determination of reaction rate constants and initial rates of the degradation process. CONCLUSION: An improved photocatalytic activity was observed with metal doping due to the synergistic effect of doped metals with commercial TiO2 and profound charge transfer among them. It was observed that performance was increased with temperature rise in the practical range of application, that is, 5–20 °C. This behavior was due to high rate of movement of charge carriers. Further, involvement and functioning of various radical species such as h+, OH− and O2− in nitrobenzene degradation were successfully established using appropriate radical scavengers. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Lanthanide ion contained metal–organic frameworks (MOFs) have garnered significant attention in the fields of solid‐state lighting and chemical sensing due to their porous structure and distinctive optical properties. However, they also present challenges because of the limited photoluminescence (PL) intensity resulting from the parity‐forbidden f–f transitions of lanthanide ions. Herein, the study reports a new heterometallic MOFs Ln3Li2L4 (Li‐Ln‐MOF, Ln = Y, Eu, Tb and Dy, L = deprotonated 1,3,5‐tris(4‐carboxyphenyl)benzene) with a Brunauer‐Emmett‐Teller (BET) surface area of 774.1 m2/g. The porous crystal structure of Li‐Ln‐MOF is characterized by three kinds of channels interpenetrating with each other. By employing ligand alternation and lanthanide ion alloying strategies, Li‐Y1‐xEux‐MOF1 crystal isostructural with Li‐Ln‐MOF is synthesized by using 2,4,6‐tris(4‐carboxyphenyl)‐1,3,5‐triazine (H3TATB) as ligand. The Li‐Y0.7Eu0.3‐MOF1 crystal excels in the comprehensive performance with a BET surface area of 858.8 m2 g−1 and a near‐unity PL quantum yield. The time density functional theory and natural transition orbitals calculations unravel that the outstanding optical properties Li‐Y0.7Eu0.3‐MOF1 originates from the charge transfer between TATB3− and Eu3+. Benefiting from the excellent comprehensive performance of Li‐Y1‐xEux‐MOF1, the study reveals their potentials as single‐composition white‐light emission and fluorescent sensing probe for the detection of nitrobenzene. [ABSTRACT FROM AUTHOR]

Biochar-supported ZVI have received increasing attention for their potential to remove nitrobenzene in groundwater and soil. However, the capacity of this material to enhance the biological reduction of nitrobenzene and alter microbial communities in anaerobic groundwater have not been explored. In this study, the nitrobenzene removal performance and mechanism of modified biochar-supported zerovalent iron (ZVI) composites were explored in anaerobic soil. The results showed that the 700 °C biochar composite enhanced the removal of nitrobenzene and inhibited its release from soil to the aqueous phase. NaOH-700-Fe50 had the highest removal rate of nitrobenzene, reaching 64.4%. However, the 300 °C biochar composite inhibited the removal of nitrobenzene. Microbial degradation rather than ZVI-mediated reduction was the main nitrobenzene removal pathway. The biochar composites changed the richness and diversity of microbial communities. ZVI enhanced the symbiotic relationship between microbial genera and weakened competition between soil microbial genera. In summary, the 700 °C modified biochar composite enhanced the removal of nitrobenzene by increasing microbial community richness and diversity, by upregulating functional genes, and by promoting electron transfer. Overall, the modified biochar-supported ZVI composites could be used for soil remediation, and NaOH-700-Fe50 is a promising composite material for the on-site remediation of nitrobenzene-contaminated groundwater. [ABSTRACT FROM AUTHOR]

Seven new lanthanide coordination polymers, namely [Ln(cpt)3H2O)]n(Ln = La (1), Pr (2), Sm (3), Eu (4), Gd (5), Dy (6), and Er (7)), which were synthesized under hydrothermal conditions using 4′-(4-(4-carboxyphenyloxy)phenyl)-4,2′:6′,4′-tripyridine (Hcpt) as the ligand. The crystal structures of these seven complexes were determined using single-crystal X-ray diffraction, and they were found to be isostructural, crystallizing in the triclinic P 1 - space group. The Ln(III) ions were nine-coordinated with tricapped trigonal prism coordination geometry. The Ln(III) cations were coordinated by carboxylic and pyridine groups from (cpt)− ligands, forming one-dimensional ring-chain structures. Furthermore, the luminescent properties of complexes 1–7 were investigated using fluorescent spectra in the solid state. The fluorescence sensing experiments demonstrated that complex 4 exhibits high selectivity and sensitivity for detecting Co2+, Cu2+ ions, and nitrobenzene. Moreover, complex 3 shows good capability for detecting Cu2+ ions and nitrobenzene. Additionally, the sensing mechanism was also thoroughly examined through theoretical calculations. [ABSTRACT FROM AUTHOR]