Amount Of Sodium Hydroxide Research Articles

Evaluation of Alkali-Pretreated Soybean Straw for Lignocellulosic Bioethanol Production

Soybean straw is a renewable resource in agricultural residues that can be used for lignocellulosic bioethanol production. To enhance enzymatic digestibility and fermentability, the biomass was prepared with an alkali-thermal pretreatment (sodium hydroxide, 121°C, 60 min). The delignification yield was 34.1~53%, in proportion to the amount of sodium hydroxide, from 0.5 to 3.0 M. The lignin and hemicellulose contents of the pretreated biomass were reduced by the pretreatment process, whereas the proportion of cellulose was increased. Under optimal condition, the pretreated biomass consisted of 74.0±0.1% cellulose, 10.3±0.1% hemicellulose, and 10.1±0.6% lignin. During enzymatic saccharification using Cellic® CTec2 cellulase, 10% (w/v) of pretreated soybean straw was hydrolyzed completely and converted to 67.3±2.1 g/L glucose and 9.4±0.5 g/L xylose with a 90.9% yield efficiency. Simultaneous saccharification and fermentation of the pretreated biomass by Saccharomyces cerevisiae W303-1A produced 30.5±1.2 g/L ethanol in 0.5 L fermented medium containing 10% (w/v) pretreated biomass after 72 h. The ethanol productivity was 0.305 g ethanol/g dry biomass and 0.45 g ethanol/g glucose after fermentation, with a low concentration of organic acid metabolites. Also, 82% of fermentable sugar was used by the yeast for ethanol fermentation. These results show that the combination of alkaline pretreatment and biomass hydrolysate is useful for enhancing bioethanol productivity using delignified soybean straw.

Salting-out assisted liquid-liquid extraction coupled with hydrophilic interaction chromatography for the determination of biguanides in biological and environmental samples

A new salting-out assisted liquid-liquid extraction (SALLE) sample preparation method for the determination of the polar anti-diabetic biguanide drugs (metformin, buformin and phenformin) in blood plasma, urine and lake water samples were developed. The SALLE was performed by mixing samples (plasma (0.2mL), urine or lake water (1.0mL)) with acetonitrile (0.4mL for plasma, 0.5mL for urine or lake water), sodium hydroxide powder was then added for the phase separation. The effects of type of salting-out reagent, type of extraction solvent, volumes of acetonitrile and sample, amount of sodium hydroxide, vortexing and centrifugation times on the extraction efficiency were investigated. The upper layer, containing the biguanides, was directly injected into a HPLC unit using ZIC-HILIC column (150mm×2.1mm×3.5μm) and was detected at 236nm. The method was validated and calibration curves were linear with r2>0.99 over the range of 20–2000μgL−1 for plasma and 5–2000μgL−1 for urine and lake water samples. The limits of detection were in the range (3.8–5.6)μgL−1, (0.8–1.5)μgL−1 and (0.3–0.8)μgL−1 for plasma, urine and lake water, respectively. The accuracies in the three matrices were within 87.3–103%, 87.4–109%, 82.2–109% of the nominal concentration for metformin, buformin and phenformin, respectively. The relative standard deviation for inter- and intra −day precision were in the range of 1.0–17% for all analytes in the three matrices.

Sodium Hypochlorite Pentahydrate Crystals (NaOCl·5H2O): A Convenient and Environmentally Benign Oxidant for Organic Synthesis

The novel oxidant of sodium hypochlorite pentahydrate (NaOCl·5H2O) crystals is now available for industrial and laboratory use. It is superior to conventional aqueous sodium hypochlorite solutions (aq. NaOCl). The crystalline material is 44% NaOCl and contains minimal amounts of sodium hydroxide and sodium chloride, and the aqueous solution, which is prepared from NaOCl·5H2O and water, has a pH of 11–12. Examples of the selective organic synthesis using NaOCl·5H2O involve the oxidations of primary and secondary alcohols, selective oxidations to sulfoxide and sulfone, oxidative cleavage of disulfide to sulfonyl chloride and bromide, oxaziridine synthesis, and oxidative dearomatization of phenols.

Extraction and physicochemical characterization of chitin and chitosan from Zophobas morio larvae in varying sodium hydroxide concentration

Large amount of sodium hydroxide (NaOH) is consumed to remove the protein content in chitin biomass during deproteinization. However, excessive NaOH concentration used might lead to the reduction of cost effectiveness during chitin extraction. Hence, the present study aimed to extract and evaluate the physicochemical properties of chitin and chitosan isolated from superworm (Zophobas morio) larvae using 0.5M–2.0M of NaOH. The extracted chitin and chitosan were subjected to Fourier Transform Infrared Spectroscopy (FT-IR), elemental analysis, Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD). The 0.5M NaOH treatment resulted in the highest yield of chitin (5.43%), but produced the lowest yield (65.84%) of chitosan. The extracted chitin samples had relatively high degree of acetylation (DA) (82.39%-101.39%). Both chitin and chitosan showed smooth surface with tiny pores. The extracted chitin samples were confirmed as α-chitin based on the FT-IR and TGA. The chitin samples were amorphous with low degree of crystallinity. From TGA, the Chitosan 3 extracted was partially deacetylated. Both DPPH radical scavenging and ferric-chelating assay showed positive correlation with DD of chitosan isolates. However, the chitosan isolates were not fully dissolved, resulting in lower radical scavenging and ferric-chelating ability compared to commercial chitosan.

Research on the effect of alkali roasting of copper dross on leaching rate of indium

The byproduct copper dross produced during refining crude lead was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and fluorescence spectrometer (XRF), which showed that copper dross mainly contained lead, copper, zinc, arsenic, antimony, bismuth, sulfur and a small amount of indium and silver etc. The mineralogical phase change of oxidation roasting of copper dross by adding sodium hydroxide was analyzed with the help of XRD and SEM. The effects of water leaching, ratio of sodium hydroxide, roasting time, and roasting temperature on leaching rate of indium were investigated mainly. The experimental results showed that phase of lead metal and sulfides of lead, copper and zinc disappeared after oxidation roasting of copper dross by adding sodium hydroxide, new phase of oxides of lead, copper, zinc and sodium salt of arsenic and antimony appeared. Water leaching could remove arsenic, and acid leaching residue obtained was then leached with acid. The leaching rate of indium was higher 6.98% compared with alkali roasting of copper dross-acid leaching. It showed that removing arsenic by water leaching and acid leaching could increase the leaching rate of indium and be beneficial to reducing subsequent acid consumption of extracting indium by acid leaching. The roasting temperature had a significant effect on the leaching rate of indium, and leaching rate of indium increased with the rise of roasting temperature. When roasting temperature ranged from 450°C to 600°C, leaching rate of indium increased significantly with the rise of roasting temperature. When roasting temperature rose from 450°C to 600°C, leaching rate of indium increased by 60.29%. The amount of sodium hydroxide had an significant effect on the leaching rate of indium, and the leaching of indium increased with the increase of the amount of sodium hydroxide, and the leaching rate of indium was obviously higher than that of copper dross blank roasting and acid leaching.

Synthesis, physical-chemical and biological properties of 7-benzyl-3-methyl-8-thioxanthine derivatives

Introduction . Interest to the problem of creating new effective antimicrobial agents among xanthine derivatives does not decrease. Primarily, this is due to the increasing of microbial resistance to conventional antimicrobial agents and the emergence of their new strains. In recent years interest to the therapeutic use of antioxidants in the treatment of diseases associated with oxidative stress has increased.The aim of this work is to elaborate simple laboratory methods of 7-benzyl-3-methyl-8-thioxanthine derivatives synthesis, unspecified in scientific papers earlier, and to study their physical, chemical and biological properties.Materials and methods. The melting point has been determined with the help of an open capillary method with PTP-M device. Elemental analysis has been performed with the help of the instrument Elementar Vario L cube, NMR-spectra have been taken on a spectrometer Bruker SF-400 (operating frequency of 400 MHz, solvent DMSO, internal standard – TMS). Study of antimicrobial and antifungal activity of synthesized compounds has been performed by two-fold serial dilution method. Standard test strains have been used for the study: Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 885-653. Dimethylsulfoxide was used as the solvent of the compounds.Results. Under short-time heating up of the initial 7-benzyl-3-methyl-8-thioxanthine with alkyl, alkenyl, benzyl halides or heteroalkylchlorides in a water-propanol-2 mixture in the presence of an equimolar amount of sodium hydroxide leads to the formation of 8-S-substituted of 7-benzyl-3-methylxanthines. Structure of synthesized compounds was definitely proved by NMR-spectroscopy. We conducted primary screening research of antimicrobial activity of 7-benzyl-3-methyl-8-thioxanthine derivatives, which revealed moderate and weak activity in concentrations 50-100 mcg/ml. Most of the obtained compounds showed a pronounced antifungal effect. It was established that synthesized substances have weak antioxidant activity.Conclusions. Accessible laboratory methods have been elaborated for synthesis of 7-benzyl-3-methyl-8-thioxanthine derivatives. The NMR spectral characteristics of the synthesized compounds have been analyzed and interpreted. Antimicrobial, antifungal and antioxidant activities of the obtained compounds have been explored. Priorities for further research of biologically active compounds have been outlined.

Comparison of Mechanical Properties of Biocomposites between Polybutylene Succinate/Corn Silk and Polybutylene Succinate/Cellulose Extracted from Corn Silk

Corn silk (CS) is agricultural wastes with high cellulose content and polybutylene succinate (PBS) now is more interesting in production of plastic products due to be biopolymer and high flexibility but it is lack of stiffness and strength. Therefore, the goal of this work was to study the possibility of cellulose extraction from CS fiber which was characterized by Fourier Transform Infrared Spectrometer (FTIR) for using cellulose as a reinforcing filler in PBS. Moreover, the mechanical properties (e.g. flexural and impact testing) of PBS/cellulose biocomposite were investigated and compared with that of neat PBS and PBS biocomposite adding various amounts of sodium hydroxide (NaOH) treated CS. The FTIR results showed the contents of hydroxyl (-OH) and ketone (C=O) groups in extracted CS were lower than ones of virgin CS. It was indicated that hemicellulose and lignin were more removed during extraction process, finally obtained ‘cellulose’. For mechanical testing, both cellulose and treated CS filled in PBS affect the decreased impact strength of PBS biocomposites while flexural strength and flexural modulus were increased. Furthermore, the flexural properties were reduced with enhancing filler contents from 1-15 phr for both fillers. By comparison, the flexural properties of PBS/cellulose were slightly lower than that of PBS/treated CS whereas its impact property was quite higher, especially for 10 phr cellulose loading. Therefore, cellulose can be taken more advantage for composite production by ductile property retention of PBS compared with treated CS. In addition, both cellulose and treated CS can be use as reinforcing filler for polymer to improve stiffness and strength.

Synthesis, physical-chemical properties of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acid esters

The nitrogen-containing heterocyclic systems from the class of 1,2,4-triazole derivatives, which exhibit wide range of actions, occupy special place among the variety of heterocyclic compounds. Derived biologically active substances are actively introduced into practice as new original and effective drugs. We were interested in esters of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acids, which exhibit high biological activity and can be intermediates for the synthesis of amides, hydrazides, ylidenderivatives of corresponding acids.The aim of this work is the synthesis of new esters of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acids and the establishment of their physical-chemical properties.Materials and methods. Melting point was determined by open capillary method on the device OptiMelt MPA100. The elemental composition of the synthesized compounds was determined on the universal analyzer ElementarVario ЕL cube (CHNS) (standard – sulfanilamide). 1H NMR spectra were recorded on spectrometer Varian Mercury VX-200 (1H, 200 MHz) in the solvent dimethyl sulfoxide-d6 (tetramethylsilane internal standard) and decoded using a program ADVASP(tm) Analyzer program (Umatek International Inc.). Chromato-mass-spectral studies were performed on hazarding chromatograph Agilent 1260 Infinity HPLC equipped with mass spectrometer Agilent 6120 (ionization electro-spray (ESI).The results and discussion. Synthesis of 11 new compounds, namely esters of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acids was carried out by two methods. According to the A method the alkylation of previously synthesized 3-(adamantan-1-yl)-1H-1,2,4-triazole-5-thiol was performed with the use of corresponding methyl ester of 2-chloroacetic acid and the presence of equivalent amount of sodium hydroxide. The B method involves the etherification of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acid with the use of methyl, ethyl, i-propyl, n-propyl and n-butyl alcohols in the presence of concentrated sulfuric acid. Compounds, which were obtained by different methods, do not give depression of the melting point. It should be noted that the practical yield of the reaction according to the A method is a little bit higher in comparison with the B method. Conclusions. The study of 11 new synthesized compounds, namely esters of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acids has been performed.The structure of the synthesized compounds has been confirmed by modern instrumental methods of analysis (1H NMR spectroscopy, IR spectrophotometry, gas chromatography-mass spectrometry and elemental analysis).

Two-Stage Crystallization of Meso- and Macroporous MFI and MEL Zeolites Using Tributylamine-Derived Diquaternary Ammonium Cations as Organic Structure-Directing Agents

Abstract Meso- and/or macroporous zeolites have received particular attention because the presence of secondary meso- and/or macropores, in addition to the intrinsic micropores of zeolites, can provide additional cavities at a nanometer-length scale and shorten molecular diffusion path lengths. Here, synthesis of meso- and macroporous MFI and MEL aluminosilicate zeolites via a two-stage crystallization method using diquaternary ammonium cations (N,N,N,N′,N′,N′-hexabutylheptanediammonium, Bu6-diquat-7) as an organic structure-directing agent (OSDA) is described. In this two-stage process, both low- and high-temperature stages were found to be crucial for the formation of zeolites. By carefully varying the amount of sodium hydroxide in the reactants, both MFI and MEL zeolites can be obtained with the same OSDA. It was revealed that Bu6-diquat-7 was more selective to the formation of MFI and MEL zeolites than its monoquaternary counterpart (i.e., tetrabutylammonium) under the present synthesis conditions. Interestingly, the synthesis time of the first (low temperature) stage highly influenced the particle sizes of the resulting zeolites; zeolites with smaller sizes were obtained when the synthesis time was prolonged. Gas physisorption analyses and scanning transmission electron microscopy observation suggested that the obtained zeolites possessed ink-bottle-like pores consisting of meso- and macroporous internal cavities with very narrow pore necks.

Determination of Ammonium in Aqueous Samples by Gas Phase Light Scattering Using Hydrogen Chloride Gas as a Derivatizing Reagent Followed by Nondispersive Atomic Fluorescence Spectrometry.

A sensitive method was developed for the determination of ammonium in an aqueous solution based on gas phase light scattering. In a stream of carrier gas, the gaseous ammonia from the alkalized solution formed a volatile ammonium chloride derivative by reacting with gaseous hydrogen chloride; the gaseous ammonium chloride was analyzed by nondispersive atomic fluorescence spectrometry. The mechanisms of the method are elucidated based on evaporative light scattering detection. Parameters such as temperature, amount of sodium hydroxide, and carrier gas flow rate were studied. Under optimal conditions, the detection limit of ammonium-nitrogen was 0.045 μg. The method was successfully applied to the determination of ammonium in certified reference materials, and tap and seawater samples.

Influence of Sodium Hydroxide on the Austenitic 330Cb Alloy Oxidation at High Temperature

Sodium hydroxide is found on metallic conveyor belts as residue of the degreasing process of metallic screws put inside heat treatment furnaces at 900 °C. The 330Cb (Fe-34Ni-23Cr-1Nb-1.55Si) alloy is used to build these conveyor belts. With time, the amount of sodium hydroxide increases on the 330Cb steel surface. The aim of this work is to show the influence of the NaOH amount on the 330Cb oxidation during 48 h, at 900 °C. Results show that, on this austenitic steel, a protective silica scale formation is promoted by low oxygen containing gaseous environments and the high alloy silicon content. With low NaOH deposits the oxide layer is adherent and a SiO 2 cristobalite subscale is formed. It is also demonstrated that sodium combines with niobium to form NaNbO 3. When the NaOH amount exceeds 0.265 mg.cm-2 on the alloy surface, severe oxidation is observed leading to a fast growing FeCr 2 O 4 oxide scale.

Methylene blue oxidation over iron oxide supported on activated carbon derived from peanut hulls

In order to contribute to the environment preservation, catalysts based on iron oxides supported on activated carbon were prepared from peanut hulls and evaluated in Fenton reaction to remove methylene blue from model wastewaters. The activated carbons were prepared by simultaneous carbonization and activation of peanut hulls with low amounts of sodium hydroxide and then impregnated with iron nitrate solutions to get samples with 5, 7.5,10, 12.5 and 15wt.% Fe. All solids were microporous and made of hematite and magnetite supported on activated carbon. The amount of magnetite changed with iron content and was related to surface oxidation, producing more oxygenated groups (carboxylic acids, lactones, carboxylic anhydrides and phenols) than activated carbon. Both activated carbons and iron-based catalysts were able to remove methylene blue from aqueous streams by adsorption and oxidation, the activity of activated carbon being assigned to oxygenated groups. For iron oxide-based catalysts, the adsorption capacity was related to the increase of surface oxygenated groups while the oxidation activity was assigned to the amount and crystals size of magnetite, besides the surface oxygenated groups. The association of these properties led to catalysts with close performances, being the catalyst with 10wt.% Fe slightly more efficient than the others in dye removal. The obtained catalysts produced low amounts of byproducts, being promising to remove dyes in industrial wastewaters. In addition, they have the advantage of being prepared with less sodium hydroxide than the traditional preparations, decreasing the amount of wash water, besides reducing the amounts of peanut hulls disposed in the environment.

Intumescence behaviour of bottom ash based geopolymer mortar through microwave irradiation – As affected by alkali activation

In this research the effect of alkali over the microwave enhanced bottom ash based geopolymer foam, is studied. Various samples using bottom ash and sodium silicate were prepared by varying the amounts of alkali. The higher amounts of alkali were compensated by reducing the sodium silicate percentages in order to keep the relative amounts of bottom ash and other ingredients constant. In the absence of alkali activation, the expansion in the slurry is more compared to alkali activated slurry but the porosity distribution is not so uniform as in the case of alkali activated geopolymer foam. Furthermore, a pipe also appeared in the center of non-alkali treated samples. The porosity was uniform in morphology and distribution from top to bottom for the alkali activated geopolymer foams hence properties as well. The increased amount of sodium hydroxide enhanced the properties till 5% by weight. The strength is found to be more by the use of alkali upto 3.15MPa with 5% sodium hydroxide solution. The properties developed in the foams are justified by the TGA, DTA, FTIR and SEM analysis. Higher surface area was obtained for the samples without alkali activation compared to alkali activated samples.

Kinetic study for benzyloxylation of p-bromotoluene using phase transfer catalyst assisted by microwave irradiation

The synthesis of 4-benzyloxy toluene was successfully carried out by reacting the sodium benzyloxide (BnO−Na+) with p-bromotoluene and sodium hydroxide/phase transfer catalyst system at 50°C under microwave irradiation. The nucleophilic susbstitution reaction was well explained by comparing the phase transfer catalyst system and microwave irradiation. The chemical kinetics of the reaction depends on the amount of catalyst, amount of sodium hydroxide, effect of phase-transfer catalysts, volume of benzylalcohol (BnOH) and temperature on the transformation of the reaction were studied.

Effect of Annealing Temperatures on Oxygen Reduction Reaction and Structure of Nitrogen and Sulfur Co-Doped Mesoporous Carbon Prepared from Polyquaternium-46

Mesoporous carbon materials have been used for numerous applications such as adsorption1, separation2, supercapacitor3 and oxygen reduction reaction (ORR)4 due to their preeminent textural characteristics, high surface area, mechanical stability and mesoporous structure. The properties of mesoporous carbon materials base on not only the sizes and location of the pore, but the heteroatoms doped into the carbon framework. Abundant experimental studies have certified that chemical doping of mesoporous carbon with foreign atoms, especially nitrogen and sulfur, can improve its electrochemical properties of ORR, as well as lead to new functions5. It is believed that the quantity of N-doped and S-doped in carbon will be vastly different if it was annealed at various reaction temperatures6. Herein, we use N and S co-doped mesoporous carbon which is prepared by Polyquaternium as a starting material to investigate the reaction in N2at various temperatures. The nitrogen and sulfur co-doped mesoporouss carbon electrode materials (Fe-LH) were prepared by homogeneously dispersion of polyquaternium-46 (Luviquat- HOLD) and ferrous chloride (FeCl2·4H2O) precursors onto the surface of silica (which was firstly dispersed in hydrochloric acid solution by ultrasonication, the metal loading with respect to silica is 15 wt.% ). After dried overnight, the resulting solid was ground to a fine powder, and then calcined at temperatures from 700, 800 and 900℃ to form the different structure for 1h in nitrogen atmosphere. The excess amount of sodium hydroxide (NaOH) was added to vacate the silica and the resulting powder was acid-leached using 0.5 M H2SO4at 80℃ to remove the unreacted metallic Fe. Then, the catalytic graphitization of the impregnated carbon was subjected heat treatment at 700 to 900℃ for 1h pyrolyzation time again. Besed on these method, we obain the mesoporous carbon with high porosity, and the electrocatalytic activity on the it was investigated using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) employing rotating ring-disk electrode (RRDE) Fig. 1 shows CV responses of Fe-LH-800℃ in N2/O2 saturated 0.1 M KOH solution. In the case of a N2-saturated solution, the cyclic voltammogram only presents a featureless quasi-rectangular trace. However, when O2 is introduced into the solution, a distinct ORR response with the peak potential (Ep) at 0.82 V vs. RHE, and the peak current density (Ip) of 3.61 mA cm-2can be clearly observed, indicating that this Fe-LH-800℃ catalyst has a profound catalytic ORR activity. Fig. 2 shows the polarization curves of the Fe-LH-700℃, Fe-LH-800℃ and Fe-LH-900℃ catalysts. It can be seen that the high activity of Fe-LH-800℃ for oxygen reduction was clearly demonstrated by onset potential of 0.88V, half-wave potential of 0.83V, which are positively shifted more than 93 and 36 mV, respectively, compared to Fe-LH-700℃ and Fe-LH-900℃. Reference 1. K.M. Nelson, S.M. Mahurin, R.T. Mayes, B. Williamson, C.M. Teague, A.J. Binder, L. Baggetto, G.M. Veith, S. Dai, Microporous Mesoporous Mater. 222, 94 (2016) . 2. J.G. Zhou, Y.F. Wang, J.T. Wang, W.M. Qiao, D.H. Long, L.C. Ling, J. Colloid Interface Sci. 462, 200 (2016) . 3. W.Z. Chen, J.J Shi, T.S. Zhu, Q. Wang, J.L. Qiao, J.J. Zhang, Electrochem. Acta. 177, 327 (2015) . 4. G.J. Tao, L.X. Zhang, L.S. Chena, X.Z. Cuia, Z. Huaa, M. Wanga, J.C. Wanga, Y. Chena, J.L. Shia, Carbon, 86, 108 (2015) . 5. C. Han, X.J. Bo, Y.F. Zhang, M. Li, L.P. Guo, J. Power Sources. 272, 267 (2014) . 6. S.B. Yang, L.J. Zhi, K. Tang, X.L. Feng, J. Maier, K. Müllen, Adv. Funct. Mater, 22, 3634 (2012) . Figure 1

High Performance Fe- and N- Doped Hierarchically Porous Carbons Catalyst Derived from Polyquaternium for Oxygen Reduction

The heteroatom (N, S, Cl, B, P, Fe, Co, Mn or Ni)-doped carbon materials, such as carbon nanotubes (CNTs)1, graphene2, graphitic arrays3, and amorphous carbon4, have drawn great attention due to their excellent electrocatalytic performance for ORR. However, among all these non-precious carbon-based catalysts, very few are on a competitive level with platinum in acidic media. One family of these most promising alternatives to Pt are mainly the Fe/N co-doped carbon materials. Transition metal was found to be indispensable to catalyze the graphitization of nitrogen−carbon precursor to form the highly graphitized carbon. In addition, Some studies argued that metals could not only help the formation of active sites, but could be an integral active part of the catalytic site5. Based on the above conceptions, we studied the effect of Fe content on the catalyst performance by varying initial FeSO4 7H2O/Polyquaternium weight ratio to tune the final Fe content in the catalyst. The obtained optimal catalyst (N/Fe-PAD) showed a comparable ORR activity in acidic media with commercial Pt/C. The N/Fe-doped porous carbon electrode materials(N/Fe-PAD) were prepared by homogeneously dispersion of polyquaternium (PAD) and ferrous sulfate (FeSO4 7H2O) precursors onto the surface of silica (which was firstly dispersed in hydrochloric acid solution by ultrasonication, the FeSO4 7H2O/Polyquaternium weight ratio is 0.04 and 1.0, respectively). After dried overnight, the resulting solid was ground to a fine powder, and then calcined at 800oC for 1h in nitrogen atmosphere. The excess amount of sodium hydroxide (NaOH) was added to vacate the silica and the resulting powder was acid-leached using 0.5 M H2SO4 at 85oC to remove the unreacted metallic Fe. Then, the catalytic graphitization of the impregnated carbon was subjected heat treatment at 800oC for 1h pyrolyzation time again. The catalysts as-prepared are thus designated as N/FeX-PAD(X=0.04 and 1.0, respectively). The electrocatalytic activity on the N/FeX-PAD and Pt/C was investigated using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) employing rotating disk electrode (RDE) technique in 0.1M HClO4. Fig. 1 shows CV responses of N/Fe1.0-PAD in N2/O2 saturated 0.1 M HClO4 solution. In the case of a N2-saturated solution, the cyclic voltammogram only presents a featureless quasi-rectangular trace. However, when O2 is introduced into the solution, a distinct ORR response with the peak potential (Ep) at 0.61 V vs. RHE, and the peak current density (Ip) of 2.64 mA cm-2 can be clearly observed, indicating that this N/Fe1.0-PAD catalyst has a profound catalytic ORR activity. Figure 2 shows the polarization curves of the N/Fe1.0-PAD, N/Fe0.04-PAD and Pt/C catalysts. It can be seen that the high activity of N/Fe1.0-PAD for oxygen reduction was clearly demonstrated by onset potential of 0.80V, half-wave potential of 0.68V, which are positively shifted more than 25 and 80 mV, respectively, compared to N/Fe0.04-PAD. In addition, the limiting current densities for N/Fe1.0-PAD are improved greatly (～7.5 mA cm-2 at 0.30 V), much higher than Pt/C catalyst. Reference 1. S.Y. Wang, E. Iyyamperumal, A. Roy, Y.H. Xue, D.S. Yu, L.M. Dai, Angew. Chem. Int. Ed. 50, 11756 (2011). 2. Y. Li, Y. Zhao, H.H. Cheng, Y. Hu, G.Q. Shi, L.M. Dai, and L.T Qu, J. Am. Chem. Soc. 134, 15(2012). Electrochem. Acta, 80, 213 (2012) 3. J. Liang, Y. Zheng, J. Chen, J. Liu, D. Hulicova-Jurcakova, M. Jaroniec, S.Z. Qiao, Angew. Chem. Int. Ed. 51, 3892 (2012). 4. W. Yang, T.P. Fellinger, M. Antonietti, J. Am. Chem. Soc. 133, 206 (2011). 5. X.J. Zhou, Z.Y. Bai, M.J. Wu, J.L. Qiao, Z.W. Chen, J. mater. Chem. 3, 3343-3350 (2015).­ Figure 1

Controllable Synthesis and Catalytic Property of Novel Copper Oxides (CuO and Cu<sub>2</sub>O) Nanostructures

Copper oxides (CuO and Cu2O) semiconductor micro- and nanostructures have been selectively synthesized using cupric nitrate trihydrate (Cu(NO3)2•3H2O), potassium biphthalate (KHC8H4O4) and sodium hydroxide (NaOH) as starting materials in water solution by a simple hydrothermal method. The phase and morphology of the products could be controlled by changing the amount of sodium hydroxide and sodium potassium biphthalate. X-ray diffraction (XRD), field scanning electron microscopy (SEM) and Raman spectra (Raman) were used to characterize the products. It was found that oval-shaped CuO, CuO nanoplates and octahedral Cu2O were prepared by adjusting the molar of the NaOH and KH C8H4O4, meaning that NaOH and KH C8H4O4 played an important role in the morphology and phase of the samples. The catalytic application in accelerating catalytic decomposition of ammonium perchlorate (AP) of the as-prepared samples was also investigated by means of differential scanning calorimetry (DSC). Compared with CuO (oval-shaped or plates), octahedral Cu2O exhibited better catalysis on thermal decomposition of AP. The present work can afford some guidance for the rationally controllable synthesis of other catalytic materials.

Ecofriendly one-pot synthesis and antiviral evaluation of novel pyrazolyl pyrazolines of medicinal interest

Ethyl 3-acetyl-1,5-diphenyl-1$H$-pyrazole-4-carboxylate reacts with a variety of arylaldehydes by grinding method in the presence of a catalytic amount of sodium hydroxide at ambient temperature to give the respective chalcones. The latter compounds react also by grinding method with nitrogen nucleophiles such as hydrazine hydrate, phenylhydrazine, and thiosemicarbazide to afford the corresponding pyrazol-3-yl pyrazolines. A series of 6-pyrazolylpyrimidine-2-thione derivatives were prepared by reaction of the above chalcones with thiourea by grinding method in the presence of a catalytic amount of sodium hydroxide at room temperature. In addition, 7-pyrazolylpyridopyrimidine-3-thione was prepared by reaction of chalcone with 6-aminothiouracil. All the newly synthesized compounds were characterized on the basis of elemental analysis and spectral data (IR, $^{1}$H and $^{13}$C NMR, mass). Moreover, some of the products were evaluated for their antiviral activity against the herpes virus at different concentrations. The results obtained indicated that compounds 4a, 4b, 4f, 5a, 5b, and 5c have promising activity.

Potential of using granite waste as raw material for geopolymer synthesis

The main objective of this work was to investigate the potential of using granite waste (GW) as raw material for geopolymer synthesis. The disposal of GW might cause many serious environmental issues. Due to the low reactivity of this aluminosilicate material in its natural state, GW was activated through alkali fusion with different amounts of sodium hydroxide. Fused materials obtained were then used to synthesize geopolymers at room temperature using sodium silicate as activator. The products were characterized using compressive strength, water resistance, XRD, IR spectroscopy and SEM/EDS analyzes. The results showed that the reactivity of GW is improved by alkali fusion method. The amount of reactive phase significantly increases with the amount of Na2O during the pre-activation process. Compressive strength results of geopolymer mortars are varying between 6.25 and 40.5MPa depending on the amount of Na2O used during the alkali fusion process.

Hydrothermal synthesis of ZnO microcakes assembled by octahedrons and their gas-sensing property

We report on the preparation of novel ZnO microcakes via a simple yet efficient hydrothermal approach. Three different ZnO microcakes are obtained by varying the amount of sodium hydroxide, and the influence of the sodium hydroxide on the growth of microcakes are discussed in order to elucidate growth mechanism of the microcakes. We also find that the microcakes are assembled by octahedrons and that the morphology is critical to tailoring the gas-sensing performance. Such octahedron-assembled ZnO microcakes show good gas-sensing properties to ethanol gas even at a low concentration.