p-Toluenesulfonic acid functionalized imidazole ionic liquids encapsulated into bismuth SBA-16 as high-efficiency catalysts for Friedel-Crafts acylation reaction.

Bismuth SBA-16 catalyst was synthesized by the hydrothermal method. Four kinds of p-toluenesulfonic acid functionalized imidazole ionic liquids were prepared by a two-step method and their molecular structures were characterized by 1H NMR and MS. The post-synthesis impregnation method was used to functionalize the Bi(10)-SBA-16 silicon mesoporous material with the ionic liquids and the obtained materials were characterized by FT-IR, XRD, BET, XPS, and TG. The results show that the volume and pore size of SBA-16 were changed by loading Bi and ionic liquids, while the three-dimensional cubic pore structure of SBA-16 was not destroyed. The composite catalyst was evaluated in Friedel-Crafts acylation of anisole with acetic anhydride. The effects of reaction temperature and the ratio of anisole and acylating agent on the acylation of anisole were investigated by experimental design. The results showed that 1.2ILc@Bi(10)-SBA-16 was used as the catalyst, the conversion of anisole was 85.41% and the yield of aromatic ketone was 69.19% under the conditions of a reaction temperature of 100 °C, a catalyst dosage of 0.5 g, a time period of 4 h and a molar ratio of 1 : 1.5. After 5 recycling runs, the reduction in the overall ratio of reactant conversion and product yield did not exceed 7.5%, indicating that 1.2ILc@Bi(10)-SBA-16 has good stability and reusability.

Catalytic Activity of Ag-Co-MCM-41 for Liquid-Phase Selective Oxidation of Styrene to Benzaldehyde.

A series of Ag-Co-MCM-41 with different metal loadings have been synthesized through the hydrothermal method. All the prepared catalysts were characterized by N2 adsorption-desorption, X-ray diffraction analysis, transmission electron microscopy. The results revealed that the structure of MCM-41 was well preserved and Ag and Co have been introduced successfully into the mesoporous channels of MCM-41. The liquid-phase catalytic oxidation of styrene on these catalysts was investigated using H2O2 as an oxidizing agent and acetone as a solvent in thermostatic water bath. The influence of metal loading, the catalyst dose, temperature, time and styrene/oxidant molar ratio on the conversion of styrene and yield and selectivity of benzaldehyde was investigated. Also, the reusability of the catalysts was evaluated.

Preparation of Biscuit-Like SO2-4/ZrO2 Catalyst for Alkylation of o-Xylene with Styrene.

We present here a facile synthesis of SO2-4/ZrO2 solid superacid by impregnating the biscuit-like mesoporous ZrO2 nanoparticles prepared by an emulsion combustion method directly into H2SO4 solution. The obtained solid acid catalyst was characterized by means of X-ray powder diffraction, transmission and scanning electron microscopy, thermogravimetry, Brunner-Emmet-Teller measurement, and infrared analysis. Its catalytic performance was examined by alkylation of o-xylene with styrene. The optimal catalytic formulation, obtained from the investigation of experimental conditions, was determined to be 5 wt% of catalyst loading with initial o-xylene/styrene molar ratio of 5 under reaction temperature at 120 °C for 120 min, achieving a 100% styrene conversion and a 93.3% 1-phenyl-1-xylyl ethane selectivity. The biscuit-like SO2-4/ZrO2 solid acid exhibited high catalytic activity and selectivity and excellent structural stability. This synthetic strategy for preparing the mesoporous SO2-4 promoted ZrO2 solid superacid catalyst is generalized and expected to be applied to other metal oxides.

B-SBA-16 encaged functional tungstosilicic acid type ionic liquids to catalyze the ketal reaction.

There is special significance to composite catalysts using SBA-16 nano-cages as carriers in the acid catalysis field. A method for embedding boron atoms onto SBA-16 to increase acidic sites and enhance the acidity of the nano-cages was described. The tungstosilicic acid type ionic liquid (SWIL) was encaged into B-SBA-16 acidic nano-cages to obtain various composite catalysts. The acidic nano-cages and composite catalysts were characterized by FT-IR, TG/DSC, SAXD, BET, SEM, TEM, XPS and 1H NMR analyses. Research confirmed that boron was embedded onto the SBA-16 nano-cages in varying proportions and the obtained B-SBA-16 acidic nano-cages still maintained a high degree of pore ordering. The SWIL was successfully encapsulated into the acidic nano-cages via the immersion method. The cage-encapsulated tungstosilicic acid type ionic liquid catalysts SWIL/B(n)-SBA-16 were applied to catalyze the ketal reaction of cyclohexanone (CYC) with ethylene glycol (EG). The results showed that the conversion of CYC could reach 92.01% along with the yield of cyclohexanone ethylene glycol ketal (CGK) of 83.87% under ideal conditions. The CYC conversion was still nearly 86.86% and the CGK yield was 69.50% even after 8 times of continuous reuse.

Ammonium Nitrate-Assisted Synthesis of Nitrogen/Sulfur-Codoped Hierarchically Porous Carbons Derived from Ginkgo Leaf for Supercapacitors.

Biomass-derived carbons for supercapacitors provide a promising and sustainable strategy to address the worldwide energy and climate change challenges. Here, we have designed and constructed three-dimensional nitrogen/sulfur-codoped hierarchically porous carbons for high-performance supercapacitor electrode materials in a one-step process, in which ginkgo leaf is used as a carbon source and S source and ammonium nitrate (AN) is used as an activating agent and a N source. During the synchronous carbonization and activation process, AN could be decomposed completely into gaseous byproducts and be removed easily without leaving residues after product formation. The as-synthesized ginkgo leaf-derived carbons exhibited a high specific capacitance of 330.5 F g-1 at a current density of 0.5 A g-1 and a capacitance of 252 F g-1 even at a high current density of 10 A g-1 with an excellent capacitance retention of 85.8% after 10 000 cycles in 6 mol L-1 KOH electrolyte. The present study provides an efficient, sustainable, and facile approach to prepare renewable hierarchically porous carbons as advanced electrode materials for energy storage and conversion.

Facile Synthesis of Acetal Over a Supported Novel Brønsted and Lewis Acid Ionic Liquid Catalyst.

A novel Brønsted and Lewis acid ionic liquid (IL) chlorinated butyrolactam chlorozincinate (CPCl-ZnCl2) was synthesized by a hydrothermal process and characterized by Fourier transform infrared (FT-IR). The Fe-SBA-15 mesoporous materials with different Si/Fe mole ratios were prepared by direct synthesis method. The supported ionic liquid (IL/Fe-SBA-15) with various IL contents were prepared by a wet impregnation method and characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N2 physical adsorption. The acidity was measured by FT-IR spectroscopy using pyridine as probes. The catalytic property was tested in acetalization of cyclohexanone with ethylene glycol. The results demonstrated that the IL/Fe-SBA-15 catalysts were of higher catalytic activity compared to Fe-SBA-15. Under optimal conditions, the acetalization could reach to 92.6% cyclohexanone conversion with 99.3% acetal selectivity. After 5 cycles, the cyclohexanone conversion decreased slightly. Also, the catalyst showed good catalytic property in the other acetalization of cyclohexanone and benzyl alcohol.

mpg-C3N4/Ag2O Nanocomposites Photocatalysts with Enhanced Visible-Light Photocatalytic Performance.

To study the photocatalytic activity under visible light irradiation, a series of mesoporous graphitic carbon nitride (mpg-C3N4)/Ag2O photocatalysts were synthesized. The as-prepared photocatalysts were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption Brunauer-Emmett-Teller method (N2-BET), Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectra (DRS), and photoluminescence spectra (PL) methods to determine their phase structure, purity, morphology, spectroscopic and photoluminescence emission performance, respectively. Photocatalytic degradation of methyl orange (MO) aqueous solution under visible-light irradiation indicated that the mpg-C3N4/Ag2O-50 nanocomposite exhibited the best activity. The degradation rate of MO reached to 90.8% in 120 min onto the mpg-C3N4/Ag2O-50 nanocomposite, and as compared with the pure mpg-C3N4 and Ag2O samples, the photocatalytic activity of the mpg-C3N4/Ag2O-50 nanocomposite was greatly enhanced. The enhancement of photocatalytic activity was mainly ascribed to the enhanced visible-light absorption ability and the formation of p-n heterojunctions between counterparts of the nanocomposites, which promoted the generation and separation of charge carriers.

Drug Release Behavior of Doxorubicin Hydrochloride-Loaded Poly(L-Lactic Acid)/Hydroxyapatite/Gelatin by Surface Modification of Hydroxyapatite.

The doxorubicin hydrochloride (DOX)-loaded poly(L-lactic acid)/hydroxyapatite/gelatin (PLLA/a-HA/gelatin) particle was prepared by emulsion/solvent evaporation method using CH2Cl2 as a solvent. HA nanoparticles were prepared via a facile chemical precipitate method and HA nanoparticles were functionalized by adding aminopropyltriethoxysilane (APTS) under microwave radiation. The physical and chemical properties of HA and modified HA were characterized by XRD, TEM, FT-IR, and XPS. Furthermore, the release of DOX from PLLA/a-HA/gelatin was also estimated. Results indicated that HA was successfully functionalized via APTS and functionalized HA has primary amino groups on its surface which improved the surface chemical compatibility between HA and PLLA matrix. The prepared PLLA/a-HA/gelatin was considered as a drug release carrier to study sustained release behavior of doxorubicin hydrochloride (DOX). The PLLA/a-HA/gelatin can effectively prolong the release time of DOX and exhibits a stable and sustainable drug release which indicates that the PLLA/a-HA/gelatin nanocomposite material could serve as a potential carrier for novel drug release system.

Removal of Cu(II) Ions from Aqueous Solution Using Fe/La-CTAB-Graphene Oxide Nanocomposite as Efficient Adsorbent.

We report an approach for synthesis of Fe/La-CTAB-graphene oxide (GO) nanocomposite with coprecipitation method prepared from natural graphite. The nanocomposite was characterized by XRD, FT-IR, SEM and TEM, and was applied to remove copper ions in aqueous system. Also, the effect of various factors such as contact time, temperature, initial concentration of Cu(II) ions, and solution pH on Cu(II) ions adsorption over Fe/La-CTAB-GO nanocomposite was investigated. The results reveal that removal percentage of Cu(II) ions is over 91% (pH = 6.0) within 90 min, along with the initial concentration of Cu(II) ions of 10 mg/L and the dose of 15 mg. The adsorption of Cu(II) ions over Fe/La-CTAB-GO nanocomposite fitted well to Langmuir isotherm model (R2 = 0.99855) and followed the pseudo-second-order kinetic (R2 = 0.99974). Thermodynamic parameters declare that the adsorption process is endothermic and spontaneous. Results of this work suggest that Fe/La-CTAB-GO nanocomposite can be a promising adsorbent for the removal of copper ions in aqueous solutions.

Fabrication and Friction Coefficient of Graphene Oxide Reinforced Hydroxyapatite Composite.

Graphene oxide (GO) reinforced hydroxyapatite (HA) composites with various contents of GO (HA/GO-C) were synthesized with addition of cetyltrimethyl ammonium bromide (CTAB) by a wetchemical precipitation method using diammonium hydrogen phosphate ((NH4)2HPO4) and calcium nitrate (Ca(NO3)2 · 4H2O) as the initial reactants, and their structure, morphology, crystallization, specific surface area were studied by FT-IR, SEM, Raman spectroscopy, XRD and BET. Particularly, the influence of GO addition and appiled load on the friction coefficient of the obtained composites was investigated. Also, the influence of GO addition on microhardness of the composite was evaluated. The results suggested that HA successfully grafted over GO nanosheets whose structure was preserved. The layer spacing of HA/GO-C composite was enlarged by addition of CTAB in synthesis process. The friction coefficient of the composite gradually decreased with increase of GO content in composite and increased with increase in applied load. The microhardness of the composites increased with increase of GO content. The obtained HA/GO-C composites may have a potential application in biomedical engineering.

Fluoride Release from Hollow Silica Microsphere-Containing Dental Restorative Acrylate Resin.

Hollow silica microspheres with mesoporous shells were prepared by the sacrificial template method. Hollow silica microsphere-containing acrylate resin-based dental restoration materials were prepared by using hollow silica microspheres as NaF reservoirs. Fluoride release performances from naked hollow silica microspheres, acrylate resin, and hollow silica microsphere-containing acrylate resin-based dental restorative materials in an artificial saliva were investigated. The results showed that hollow silica microsphere-containing acrylate resin-based dental restorative materials had higher cumulative fluoride release quantities and sustained fluoride release rates than traditional acrylate resin-based dental restorative materials. Fluoride release could be tuned by changing the mesoporous shell thickness of hollow silica microsphere.

Fabrication of a novel graphene oxide/ß-FeOOH composite and its adsorption behavior for copper ions from aqueous solution.

A graphene oxide (GO)/ß-FeOOH composite was prepared by the liquid insert method and was characterized by XRD, FT-IR, SEM and TEM. The adsorption capacity of the composite was evaluated by the removal of copper ions (Cu(2+)) from aqueous solution. The effect of initial pH, contact time and absorbent dose on the removal efficiency of Cu(2+) was investigated by batch experiments. Langmuir and Freundlich models were employed to describe the adsorption equilibrium. The adsorption kinetics was investigated by both the pseudo-first-order and pseudo-second-order kinetics models. The results showed that the GO/ß-FeOOH composite exhibited excellent adsorption capacity for Cu(2+) and under the optimum experimental conditions, the removal rate of Cu(2+) can reach ca. 93.8%. The adsorption isotherm was a good fit with the Langmuir model and the adsorption process was described by the pseudo-second-order kinetics model.

Size-controlled preparation of α-calcium sulphate hemihydrate starting from calcium sulphate dihydrate in the presence of modifiers and the dissolution rate in simulated body fluid.

Different-sized α-calcium sulphate hemihydrate (α-CSH) rods were hydrothermally prepared by converting calcium sulphate dihydrate at 110-140°C in the presence of MgCl2, sodium citrate (CANa), and sodium dodecyl benzene sulfonate (SDBS) as the modifiers. The α-CSH rods with the average diameters and the average lengths in the ranges of 2.6-5.2 and 17.5-33.1 µm, respectively, were tunably prepared. The presence of the modifiers favoured the formation of small-sized α-CSH rods. The effect of the modifiers on decreasing the diameters of α-CSH rods was in an order of SDBS>CANa>MgCl2. The dissolution rates of the different-sized α-CSH rods prepared at 140°C in simulated body fluid were in an order of α-CSH (CANa)>α-CSH (MgCl2)>α-CSH (reference)>α-CSH (SDBS). The naked and small-sized α-CSH rods had high dissolution rates. The adsorption of SDBS on the surfaces of α-CSH rods decreased their dissolution rates.

Effect of organic modifiers on the structure of nickel nanoparticles and catalytic activity in the hydrogenation of p-nitrophenol to p-aminophenol.

Spherical nickel nanoparticles with different sizes and different structures were prepared starting from nickel oxalate and using hydrazine hydrate as a reductant in the presence of citric acid, cetyltrimethylammonium bromide, Tween 40, and d-sorbitol as organic modifiers. The size and structure of the resultant nickel nanoparticles were affected by using different organic modifiers. All of the nickel nanoparticles showed higher catalytic activity and selectivity than the conventional raney Ni catalyst in the hydrogenation of p-nitrophenol to p-aminophenol. Although the catalytic activities of the resultant nickel nanoparticles generally increased with decreasing particle size, the structure of nickel nanoparticles also had an important impact on the catalytic activity.

Preparation of mesoporous titania solid superacid and its catalytic property.

Mesoporous titania (TiO(2)) was synthesized by hydrothermal method using cetyltrimethyl ammonium bromide (CTAB) as a template and using anhydrous ethanol and tetra-n-butyl titanate (TBOT) as raw materials. Mesoporous titania solid superacid and nanosized titania solid superacid catalysts were prepared by wet impregnation method. The structure and property of as-prepared samples were characterized by means of XRD, FT-IR and N(2) physical adsorption. The esterification of salicylic acid with isoamyl alcohol and the condensation of cyclohexanone with ethylene were used as model reactions to test the catalytic activities of the catalysts. On the other hand, the comparison of catalytic activities of the prepared solid superacid catalysts and the conventional liquid acid H(2)SO(4) was also carried out under the same experimental conditions. The results show that the catalytic activities of the prepared solid superacid catalysts were higher than that of the conventional liquid acid H(2)SO(4), and that the catalytic activity of mesoporous TiO(2) solid superacid is the highest among the three catalysts. Mesoporous TiO(2) solid superacid is a good catalyst for the synthesis of isoamyl salicylate or cyclohexanone ethylene ketal.