The Preparation Technique of Nanometer Molybdenum Trioxide by Hydrothermal Synthesis

2011 ◽  
Vol 117-119 ◽  
pp. 807-810
Author(s):  
Ji Wen Li ◽  
Yan Hua Ma ◽  
Fang Fang Gong ◽  
Guo Shang Zhang ◽  
Liu Jie Xu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Hydrothermal Synthesis ◽  
Reaction Temperature ◽  
Molybdenum Trioxide ◽  
Ph Value ◽  
Ultrafine Particle ◽  
Preparation Technique ◽  
Optimum Ph ◽  
Optimum Reaction ◽  
Optimal Reaction

The technique of hydrothermal synthesis is used to prepare nanometer molybdenum trioxide through controlling the parameters such as the acidification condition, the reaction temperature, the reaction time and so on. The technique is under high temperature and high pressure by water as the solvent. Synthesized molybdenum trioxide powder is characterized by XRD, SEM, and HRTEM. The optimal reaction time is 40h, the optimum reaction temperature is 170°C, and the optimum pH value is 1.0. The results indicate that powder has an ultrafine particle size, high purity, and narrow size distribution, good fluidity, light agglomerate and is perfect in crystal.

Study on Catalytic Degradation of Diesel Pollution in Seawater by Laccase

2013 ◽  
Vol 781-784 ◽  
pp. 2324-2327
Author(s):  
Xu Zheng ◽  
Xiao Cai Yu ◽  
Yun Qing Liu ◽  
Xiao Xv ◽  
Jin Fang Chen
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Sea Water ◽  
Oil Pollution ◽  
Ph Value ◽  
Degradation Process ◽  
Catalytic Degradation ◽  
Initial Concentration ◽  
Optimization Study ◽  
Optimum Reaction

Sea water joining diesel was selected to prepare simulated marine oil pollution. With the target of removing diesel from seawater, the influence of various factors on the laccase-catalyzed degradation process was discussed. The experimental results show that the laccase-catalyzed degradation process was significantly affected by laccase dosage, reaction temperature, reaction time, pH of the solution and initial concentration of diesel in the oily wastewater. A systematic optimization study was carried out through a orthogonal test on the basis of the results of the single-factor experiments,and the optimum reaction conditions of laccase catalytic degradation diesel pollutants in seawater was determined. The results indicate that under the conditions of diesel initial concentration of 0.1g/L, laccase dosage of 8mg/L, pH value of 6, the reaction temperature of 25°C and the reaction time of 4h, laccase catalytic degradation rate of diesel pollution can be up to 63.85%.

Batch Supercritical Hydrothermal Synthesis of CeO2 Nanoparticles

2011 ◽  
Vol 284-286 ◽  
pp. 773-780
Author(s):  
Dan Zhao ◽  
Da Liang Li ◽  
Xin Qiang Wu ◽  
En Hou Han
Keyword(s):  
Reaction Time ◽  
Hydrothermal Synthesis ◽  
Reaction Temperature ◽  
Ph Value ◽  
Synthesis Method ◽  
Additional Treatment ◽  
Reactant Concentration ◽  
Size And Morphology ◽  
Supercritical Hydrothermal Synthesis

CeO2 nanoparticles with diameter of about 5 nm were prepared by batch supercritical hydrothermal synthesis method at 390 °C without additional treatment. It was found that the characteristics of products depended on the pH value, reactant concentration (C0), and reaction temperature. The reaction time and coexisting cations (Li+, Na+ and K+) had little effect on the size and morphology of CeO2 particles. Uniform CeO2 nanoparticles were synthesized at 390 °C, pH = 9 and C0 = 0.06 M. The mechanism for batch supercritical hydrothermal synthesis of CeO2 nanoparticles is discussed.

scholarly journals Synthesis of propylene carbonate from urea and 1,2-propylene glycol over metal carbonates

2011 ◽  
Vol 17 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Jiancheng Zhou ◽  
Wu Dongfang ◽  
Birong Zhang ◽  
Yali Guo
Keyword(s):  
Reaction Time ◽  
Propylene Glycol ◽  
Propylene Carbonate ◽  
Reaction Temperature ◽  
Reaction Conditions ◽  
Lead Carbonate ◽  
Synthetic Process ◽  
Metal Carbonates ◽  
Optimal Reaction ◽  
Mixed Carbonate

A series of single-metal carbonates and Pb-Zn mixed-metal carbonates were prepared as catalysts for alcoholysis of urea with 1,2-propylene glycol (PG) for the synthesis of propylene carbonate (PC). The mixed carbonates all show much better catalytic activities than the single carbonates, arising from a strong synergistic effect between the two crystalline phases, hydrozincite and lead carbonate. The mixed carbonate with Pb/Zn=1:2 gives the highest yield of PC, followed by the mixed carbonate with Pb/Zn=1:3. Furthermore, Taguchi method was used to optimize the synthetic process for improving the yield of PC. It is shown that the reaction temperature is the most significant factor affecting the yield of PC, followed by the reaction time, and that the optimal reaction conditions are the reaction time at 5 hours, the reaction temperature at 180 oC and the catalyst amount at 1.8 wt%, resulting in the highest PC yield of 96.3%.

scholarly journals Optimization of Synthesis of Seleno-Sargassum fusiforme(Harv.) Setch. Polysaccharide by Response Surface Methodology, Its Characterization, and Antioxidant Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Bin Ji ◽  
Fang Dong ◽  
Miao Yu ◽  
Long Qin ◽  
Dan Liu
Keyword(s):  
Antioxidant Activity ◽  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Sargassum Fusiforme ◽  
Synthesis Conditions ◽  
Optimum Reaction ◽  
Series Of Experiments

The response surface methodology was employed to optimize the synthesis conditions of seleno-Sargassum fusiforme(Harv.) Setch. polysaccharide. Three independent variables (reaction time, reaction temperature, and ratio of Na2SeO3to SFPSI) were tested. Furthermore, the characterization and antioxidant activity of Se-SFPSIin vivowere investigated. The result showed that the actual experimental Se content of Se-SFPSI was 3.352 mg/g at the optimum reaction conditions of reaction time 8 h, reaction temperature 71°C, and ratio of Na2SeO3to SFPSIB 1.0 g/g. A series of experiments showed that the characterization of Se-SFPSIB was significantly different from that of SFPSIB. Additionally, antioxidant activity assay indicated that the Se-SFPSIB could increase catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity of mice bearing tumor S180in blood, heart, and liver while decreasing malondialdehyde (MDA) levels. It can be concluded that selenylation is a feasible approach to obtain seleno-polysaccharide which was utilized as highly biological medicine or functional food.

Synthesis of a Ruthenium Complex Based on 2,6-Bis[1-(Pyridin-2-yl)-1H-Benzo[d]Imidazol-2-yl]Pyridine and Catalytic Oxidation of (1H-Benzo[d]-Imidazol-2-yl)Methanol to 1H-Benzo[d]Imidazole-2-Carbaldehyde with H2O2

2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni
Keyword(s):  
Reaction Time ◽  
Catalytic Oxidation ◽  
Reaction Temperature ◽  
Ruthenium Complex ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
Optimal Reaction

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.

scholarly journals Facile Synthesis of Silver Nanoparticles and Preparation of Conductive Ink

Nanomaterials ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 171
Author(s):  
Gui Bing Hong ◽  
Yi Hua Luo ◽  
Kai Jen Chuang ◽  
Hsiu Yueh Cheng ◽  
Kai Chau Chang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electrical Resistivity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Chemical Reduction ◽  
Flexible Substrate ◽  
Synthesis Method ◽  
Future Research ◽  
Conductive Ink

In the scientific industry, sustainable nanotechnology has attracted great attention and has been successful in facilitating solutions to challenges presented in various fields. For the present work, silver nanoparticles (AgNPs) were prepared using a chemical reduction synthesis method. Then, a low-temperature sintering process was deployed to obtain an Ag-conductive ink preparation which could be applied to a flexible substrate. The size and shape of the AgNPs were characterized by ultraviolet–visible spectrophotometry (UV-Vis) and transmission electron microscopy (TEM). The experiments indicated that the size and agglomeration of the AgNPs could be well controlled by varying the reaction time, reaction temperature, and pH value. The rate of nanoparticle generation was the highest when the reaction temperature was 100 °C within the 40 min reaction time, achieving the most satisfactorily dispersed nanoparticles and nanoballs with an average size of 60.25 nm at a pH value of 8. Moreover, the electrical resistivity of the obtained Ag-conductive ink is controllable, under the optimal sintering temperature and time (85 °C for 5 min), leading to an optimal electrical resistivity of 9.9 × 10−6 Ω cm. The results obtained in this study, considering AgNPs and Ag-conductive ink, may also be extended to other metals in future research.

Enhanced Photocatalytic Performance and Mechanism of Ag3PO4 Particles Synthesized via a Sonochemical Process

2018 ◽  
Vol 10 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Chengxiang Zheng ◽  
Hua Yang ◽  
Yang Yang ◽  
Haimin Zhang
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Dye Degradation ◽  
Sonochemical Method ◽  
Simulated Sunlight ◽  
Spherical Nanoparticles ◽  
Direct Oxidation

A facile sonochemical method was used to synthesize Ag3PO4 particles and the effect of pH value, reaction temperature and reaction time on the products was investigated. It is found that the samples prepared at neutral (pH = 7) and alkaline (pH = 11) environments exhibit a similar particle morphology and size. The particles are shaped like spheres with a size distribution majorly focusing on a range of 200–450 nm, and the average particle size is about 300 nm. The sample prepared at acidic environment (pH = 3) is composed of polyhedral microparticles with size of 5–8 μm. At relatively low temperatures of 20–50 °C, the spherical nanoparticles do not undergo obvious morphology/size changes; however, when the temperature is increased up to 80 °C, the nanoparticles are aggregated to form large-sized polyhedral microparticles in the size range of 4–7 μm. Compared to the pH value and reaction temperature, the reaction time has a minor effect on the morphology of Ag3PO4 particles. RhB was chosen as the target pollutant to evaluate the photocatalytic activity of the as-prepared Ag3PO4 samples under simulated-sunlight irradiation. It is shown that the samples consisting of spherical nanoparticles exhibit an extremely high photocatalytic activity, and the degradation percentage of RhB after reaction for 50 min reaches over 90%. The samples of polyhedral microparticles have a relatively low photocatalytic activity, which is possibly due to their large particle size. Hydroxyl (.OH) radical was detected by spectrofluorimetry using terephthalic acid as a .OH scavenger and was not found to be produced over the simulated-sunlight-irradiated Ag3PO4 catalyst. The effect of ethanol, benzoquinone and ammonium oxalate on dye degradation was also investigated. Based on experimental results, the direct oxidation by h+ is suggested to the dominant mechanism toward the dye degradation.

Synthesis of Butanone 1,2 - Propanediol Ketal by Sulfamic Acid as Catalyzed

2013 ◽  
Vol 781-784 ◽  
pp. 276-279
Author(s):  
Yu Hang Zhao ◽  
Li Cui ◽  
Da Zhi Wang ◽  
Tong Kuan Xu ◽  
Yong Peng Li
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Raw Materials ◽  
Sulfamic Acid ◽  
Product Yield ◽  
Experimental Results ◽  
Reaction Conditions ◽  
Optimal Reaction

Butanone 1,2-propanediol ketal was synthesized by butanone and 1,2-propanediol as raw materials and sulfamic acid as catalyst. The effects of the mole ratio of raw materials agent, the dosage of the water-carrying agent and catalyst, reaction time on the product yield were discussed separately. Experimental results showed that sulfamic acid was a suitable catalyst for synthesizing of butanone 1,2-propanediol ketal. And the optimal reaction conditions are as follows: the mole ratio of butanone to 1,2-propanediol is 1:1.5, the amount of the catalyst is 2.2%, the water-carrying agent is 25ml, the reaction temperature is 358-378K and reaction time 3h. In this condition, the yield of production could reach 93.8%.

Study on Synthesis of Nitrophenyl Isocyanates Using Triphosgene

2012 ◽  
Vol 550-553 ◽  
pp. 1039-1042 ◽  
Author(s):  
Gui Rong Cao ◽  
Xue Yan Zhao ◽  
Rui Jie Xiao
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Optimum Reaction

In this paper, triphosgene respectively reacting with o-nitrophenyl aniline, m-nitrophenyl aniline and p-nitrophenyl aniline to synthesize corresponding isocyanates. The effects of reactants molar ratio, reaction time and reaction temperature on the yield were investigated. As a result, using 1,2-dichloroethane as reaction solvent, the optimum molar ratio of the three kinds of nitroaniline and triphosgene were all 2.5:1, the optimum reaction time of synthesis of o-nitrophenyl isocyanate, m-nitrophenyl isocyanate and p-nitrophenyl isocyanate respectively was 6h, 5.5h and 5h; the optimum reaction temperature of synthesis of the three kinds of nitrophenyl isocyanates were all 75°C. Under the optimal conditions, the yield of o-nitrophenyl isocyanate, m-nitrophenyl isocyanate and p-nitrophenyl isocyanate could respectively be 80.3%, 83.7% and 83.5%. The products were characterized by meltingtest, ebulliometry, IR, and HPLC

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