Ionothermal synthesis of aggregated α-Fe₂O₃ nanoplates and their magnetic properties

Aggregated α-Fe(2)O(3) nanoplates have been successfully synthesized under ionothermal conditions through the self-assembly of nanoplatelets in a side-to-side manner. During the formation process of aggregated α-Fe(2)O(3) nanoplates, pure ionic liquid media is essential for the assembly and coalescence of small nanoplatelets into final nanoplates. Moreover, the magnetic properties of the aggregated α-Fe(2)O(3) nanoplates are strongly correlated to their unique structural characteristics.     

Facile solvothermal synthesis of mesoporous Cu₂SnS₃ spheres and their application in lithium-ion batteries

Three dimensional (3D) mesoporous Cu(2)SnS(3) spheres composed of nanoparticles were synthesized by a simple solvothermal route. As anode materials for lithium-ion batteries, they delivered remarkably enhanced cycling performances. This could be attributed to the 3D mesoporous structure which may be propitious to the accommodation of volume expansion. Besides, a possible electrochemical reaction mechanism was proposed based on cyclic voltammetry (CV) testing results and confirmed by subsequent ex situ XRD studies. In addition, the influence of testing temperature on cycling performance has also been investigated.     

Ternary Cu₂SnS₃ cabbage-like nanostructures: large-scale synthesis and their application in Li-ion batteries with superior reversible capacity

In this paper, novel ternary Cu(2)SnS(3) cabbage-like nanostructures are synthesized on a large scale via a facile solvothermal route. The individual Cu(2)SnS(3) cabbage-like hierarchitecture is constructed from 2D nanosheets with thickness of about 15.6 nm. The Cu(2)SnS(3) electrodes exhibit an initial reversible capacity of 842 mAh g(-1) and still reach 621 mAh g(-1) after 50 cycles. Such an admirable performance could be related to their 3D porous structural features as well as the high electrical conductivity induced by Cu. The electrochemical properties of the 3D hierarchical nanostructures imply its potential application in high energy density Li-ion batteries.     

Controlled growth of SnO₂@Fe₂O₃ double-sided nanocombs as anodes for lithium-ion batteries

A novel heterostructure is developed by grafting 1D SnO(2) nanorods onto both sides of pre-grown 2D Fe(2)O(3) nanoflakes, forming a comb-like rather than tree-like branched nanostructure. The SnO(2) nanorod branches are determined to grow along the [001] direction on the (±001) planes of Fe(2)O(3) nanoflakes. The resulting SnO(2)@Fe(2)O(3) nanocombs show stabilized cycling performance and improved volumetric energy density compared to pristine Fe(2)O(3) nanoflakes presumably due to the integration of SnO(2) branches as well as the 3D hierarchical structural features.     

An efficient and recyclable catalytic system for carbon–sulfur coupling reaction and synthesis of 5-substituted 1H-tetrazoles

In this research paper, efficient and economical protocols for the synthesis of symmetrical sulfides and 5-substituted 1H-tetrazoles have been reported using Fe₃O₄@SBTU@Ni(II) as a heterogeneous and recoverable nanocatalyst. The noticeable features of this catalytic system are: operational simplicity, environmentally benign, easier work-up procedure, green and efficient synthetic entry to excellent yield of products in a high reusability and applicability to various starting materials and, therefore, cost efficiency.     

Probing the morphology-device relation of Fe₂O₃ nanostructures towards photovoltaic and sensing applications

A lot of research on nanomaterials has been carried out in recent years. However, there is still a lack of nanostructures that have a combination of superior properties; both efficient electron transport and high surface area. Here, the authors have tried to develop hybrid α-Fe(2)O(3) flower-like morphology which exhibits both superior electron transport and high surface area. Intrigued by the unique properties of Fe(2)O(3) at the nanoscale and its abundance in nature, we have demonstrated a facile template-free solution based synthesis of hybrid α-Fe(2)O(3) comprising nanopetals nucleating radially from a 3D core. Due to its simplicity, the synthesis process can be easily reproduced and scaled up. We carried out in-depth studies on gas sensing and dye-sensitized solar cell (DSSC) device characterization so as to gain an understanding of how surface area and transport properties are affected by variation in morphology. The hybrid α-Fe(2)O(3) nanostructures are studied as potential candidates for gas sensors and for the first time as a working electrode for DSSC.     

Controllable synthesis and electrochemical hydrogen storage properties of Sb₂Se₃ ultralong nanobelts with urchin-like structures

The controlled synthesis of one-dimensional and three-dimensional Sb(2)Se(3) nanostructures has been achieved by a facile solvothermal process in the presence of citric acid. By simply controlling the concentration of citric acid, the nucleation, growth direction and exposed facet can be readily tuned, which brings the different morphologies and nanostructures to the final products. The as-prepared products have been characterized by means of X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM and selected area electron diffraction. Based on the electron microscope observations, a possible growth mechanism of Sb(2)Se(3) with distinctive morphologies including ultralong nanobelts, hierarchical urchin-like nanostructures is proposed and discussed in detail. The electrochemical hydrogen storage measurements reveal that the morphology plays a key role on the hydrogen storage capacity of Sb(2)Se(3) nanostructures. The Sb(2)Se(3) ultralong nanobelts with high percentage of {-111} facets exhibit higher hydrogen storage capacity (228.5 mA h g(-1)) and better cycle stability at room temperature.     

Preparation of Ag-Al₂O₃ nano structures by combustion method and investigation of photocatalytic activity

In this research, Ag-Al₂O₃ nanostructures have been prepared via combustion synthesis and ammonium acetate and urea have been applied as fuels. The prepared Ag-Al₂O₃ nanostructures were characterized by DTA, XRD, SEM, TEM, and BET spectroscopy. The effect of different ratios of silver to alumina and fuel percentage on morphology and particle size of prepared products were investigated. The results showed that using ammonium acetate fuel led to the production of Ag-γ-Al₂O₃ nanocompounds, while using urea produced Ag-α-Al₂O₃. Also, the photocatalytic activity of Ag-Al₂O₃ nanostructures for Congo red degradation was evaluated by UV-Vis diffuse reflectance spectroscopy. The photocatalytic activity of Ag-Al₂O₃ was examined under UV-Vis irradiation and showed significant photocatalytic efficiency.     

A recyclable and efficient triazole ligand for the palladium-catalyzed Suzuki–Miyaura and Mizoroki–Heck reactions

A new fluoroalkylated 1,4-disubstituted [1,2,3]-triazole was prepared and acted as an efficient ligand in the palladium-catalyzed Suzuki–Miyaura coupling reactions of aryl boronic acids and aryl halides (Ar–Br and Ar–Cl) and Mizoroki–Heck reactions of aryl halides and alkenes. All reactions proceeded smoothly to give the desired products in moderate to excellent yields under the optimal conditions. Moreover, the ligand could be easily recovered by fluorous solid-phase extraction with excellent purity and reused with slightly decrease in its activity.     

Facile synthesis of two-dimensional graphene/SnO₂ /Pt ternary hybrid nanomaterials and their catalytic properties

In this paper, we reported a simple, aqueous-phase route to the synthesis of two-dimensional graphene/SnO(2) composite nanosheets (GSCN) hybrid nanostructures consisting of 5 nm Pt nanoparticles supported on the both sides of GSCN. Functional two-dimensional GSCN were obtained through the reduction of graphene oxide (GO) using SnCl(2) in the presence of polyelectrolyte poly(diallyldimethylammonium chloride) (PDDA). The main advantages of this preparation are that the reduction of GO, the formation of SnO(2) and the functionalization of GSCN were achieved simultaneously through one-pot reaction. GSCN/Pt ternary hybrid nanomaterials were generated by in situ reduction of negatively charged PtCl(6)(2-) precursors adsorbed on the positively charged surface of GSCN through electrostatic attraction. The as-synthesized GSCN/Pt ternary hybrid nanomaterials exhibited high cycle stabilization during the catalytic reduction of p-nitrophenol into p-aminophenol by NaBH(4). Additionally, our approach is expected to extend to other hybrid nanomaterials. We believe that the obtained GSCN/Pt ternary hybrid nanomaterials have great potential for applications in other field, such as electrochemical energy storage, sensors, and so on.     

β-Keto sulfones: preparation and application in organic synthesis

The review summarizes a survey of recent advances and contributions to the methods of synthesis, chemical properties and application of β-keto sulfones with the main focus on the their increasingly growing demand as starting substrates and intermediates incorporated in the syntheses of various classes of organic compounds.     

Silver nanoparticles as an efficient,heterogeneous and recyclable catalyst for synthesis of β-enaminones

A simple and efficient protocol has been developed for synthesis of β-enaminones and β-enamino esters catalyzed by silver nanoparticles as a novel, heterogeneous, moisture stable and recyclable catalyst under mild reaction conditions. The reaction was optimized with respect to various parameters such as catalyst screening, catalyst loading, different solvents and temperature. The silver nanoparticle exhibited excellent activity and the methodology is applicable to diverse substrates providing good to excellent yields of desired products. The catalyst was recycled for three consecutive cycles without any significant loss in activity.     

Synthesis and characterization of new Mg–O–F system and its application as catalytic support

The Mg–O–F system (MgF₂–MgO) with different contents of MgF₂ (100–0%) and MgO is tested as support of iridium catalysts in the hydrogenation of toluene as a function of the MgF₂/MgO ratio. Mg–O–F samples have been prepared by the reaction of magnesium carbonate with hydrofluoric acid. The MgF₂–MgO supports, after calcination at 500 °C, are classified as mesoporous of surface area (34–135 m²·g^− 1) depending on the amount of MgO introduced. The Ir/Mg–O–F catalysts have been tested in the hydrogenation of toluene. The highest activity, expressed as TOF, min^− 1, was obtained for the catalyst supported on Mg–O–F containing 75 mol%MgF₂.     

α-Zirconium phosphate supported metal–salen complex: synthesis,characterization and catalytic activity for cyclohexane oxidation

Metal–salen intercalated α-zirconium phosphate, abbreviated as {α-ZrP·M(Salen), where M = Fe(III) and Mn(II)} was synthesized insitu by the flexible ligand method. The structure of resulting compounds was characterized by BET surface area, powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, thermogravimetric analysis and UV–visible spectroscopy. The catalytic activity of α-ZrP·M(Salen) was tested for the oxidation of cyclohexane using dry tert-butylhydroperoxide as an oxidant. In the oxidation reaction, cyclohexane was oxidized to cyclohexanol (A), cyclohexanone (K) and some unidentified products. It was found that the reactivity of α-ZrP·Fe(Salen) is greater than α-ZrP·Mn(Salen) in the oxidation reaction. Influence of various reaction parameters viz. reaction temperature, catalyst concentration, substrate to oxidant molar ratio was studied using α-ZrP·Fe(Salen) catalyst to obtain maximum conversion (29.30%) of cyclohexane. The catalyst was reused for five cycles without significant loss of catalytic activity.     

Highly active recyclable SBA-15-EDTA-Pd catalyst for Mizoroki-Heck,Stille and Kumada C–C coupling reactions

Highly efficient SBA-15-EDTA-Pd(11) heterogeneous catalyst was synthesized by covalent anchoring Pd-EDTA complex over organo-modified surface of SBA-15. SBA-15-EDTA-Pd(11) catalyst was found to exhibit excellent catalytic activity in appreciable yield for Heck, Stille and Kumada cross-coupling reactions. Catalytic system exhibited excellent activity for completion of reaction, isolation, Pd loading (0.87 mmol%) and yields of products as compared to earlier reported heterogeneous supported Pd catalysts. Covalently anchored heterogeneous SBA-15-EDTA-Pd(11) catalyst can be recycled for more than five times without noticeable loss in activity and selectivity.     

Sucrose-mediated sol–gel synthesis of nanosized pure and S-doped zirconia and its catalytic activity for the synthesis of acetyl salicylic acid

Nano-sized pure and S-doped zirconia was prepared by the sol–gel method in the presence of sucrose and zirconium(IV) acetylacetonate (Zr(acac)₄) as a gelation agent and Zr⁴⁺ source, respectively. Acid catalyst activity of samples was tested for the production of acetyl salicylic acid from salicylic acid and acetic anhydride as precursors, The yield (64.0%) of acetylsalicylic acid was obtained from 50 mg of S-doped zirconia calcined at 550 °C and after a 3 h reaction, was comparably higher than the yield of the reaction (13.3%) in the absence of a catalyst and under the same reaction condition.     

Conversion of zeolite—A in to various ion-exchanged catalytic forms and their catalytic efficiency for the synthesis of benzimidazole

Zeolite-A was synthesized and converted into various ion-exchanged catalytic forms successfully. These catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer Emmett Teller (BET) surface area measurement and thermal programmed desorption (TPD). Their catalytic activity was tested on the synthesis of benzimidazole using o-phenylenediamine (OPDA) and aldehyde at room temperature. The reaction proceeds efficiently under ambient conditions. The catalysts gave a high isolated yield of benzimidazole in a shorter reaction time at room temperature and were recycled several times.     

Effect of carbon and α-Al2O3 on controlled synthesis of AlON powder

The α-Al₂O₃/C mixtures were prepared by ball milling, and then AlON powders were synthesized by carbothermal reduction and nitridation (CRN). The effects of α-Al₂O₃ particle size, carbon powders morphology and particle size on the morphology and particle size of the synthesized AlON powders were studied. The results showed that as the particle size of α-Al₂O₃ increases, the particle size of the synthesized AlON powders will also increase, but the surface morphology will not be affected. The increase of the carbon particle size will increase the particle size of the synthesized AlON powders. The pore size and number of pores of the synthetic AlON powders were very similar to the morphological characteristics of the carbon powders. In addition, the mechanism of controlling the synthesis of AlON powder with α-Al₂O₃ and carbon as raw materials was also discussed.