Influence of pH Value and Precipitant on Zn2SnO4 Formation via Co-Precipitation Method

2011 ◽  
Vol 291-294 ◽  
pp. 61-64
Author(s):  
Yu Shiang Wu ◽  
Min He Tsau
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ph Value ◽  
Particle Morphology ◽  
Nano Particles ◽  
Precipitation Method ◽  
Strong Base ◽  
Co Precipitation

Nanorod-shaped zinc stannate Zn2SnO4 (ZTO) with great photocatalytic activity was successfully synthesized via a co-precipitation method. In this paper, a strong base (NaOH) and a weak base (Na2CO3) are adopted as precipitants in order to form the precursor precipitate. The titration endpoints are fixed at pH6, pH8, and pH10 in order to adjust the solution precipitant quantity. Dependent variables above were not seen in other research before. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results show that the powders synthesized were ZTO nano-particles. Photocatalytic activity of the powders was measured utilizing a photocatalytic degradation reaction with methylene blue (MB) solution. The smallest particles were obtained by utilizing NaOH as a precipitant and adjusting pH to 6. Based on TEM images, the ZTO had nano-rod particle morphology. However, when precipitant Na2CO3 was utilized, particles agglomerated together, reducing specific surface area. Hence, the former sample shows better photocatalytic activity than the latter one. Consequently, powders titrated to pH6 by precipitant NaOH and calcined for 1 hour will form partly nano-rod particles with slight agglomeration, increasing the specific surface area of ZTO and bringing about the best photocatalytic characteristics.

Synthesis and Photocatalytic Property of BiVO4/FeVO4 Composite Novel Photocatalyst

2010 ◽  
Vol 129-131 ◽  
pp. 784-788 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Dong Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photocatalytic Property ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Triclinic Phase ◽  
Xrd Patterns

BiVO4/FeVO4 composite photocatalyst samples were prepared by calcining the mixture of FeVO4 and BiVO4 precusor which were prepared through liquid phase precipitation method for further increasing the photocatalytic efficiency of FeVO4. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microsoope（SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns indicate that BiVO4/FeVO4 composite photocatalysts consist of triclinic phase and the lattice was not distorted beacause of doping Bi. But the morphology change greatly and the specific surface area has little change. In the experimental conditions used, the optimal photocatalytic activity for all the prepared samples was reached when BiVO4 doping was 22 at%. The degradation rate of MO was increased by 20％ or so than that of pure FeVO4.

Study on Cu-Based Catalysts for Synthesis of Indole

2011 ◽  
Vol 295-297 ◽  
pp. 668-671 ◽  
Author(s):  
Jun De Xing ◽  
Xiao Fei Jia
Keyword(s):  
Grain Size ◽  
Ethylene Glycol ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Precipitation Method ◽  
Impregnation Method ◽  
Co Precipitation

A series of Cu-based catalysts for the synthesis of indole by the reaction of aniline and ethylene glycol were prepared and characterized by ICP-AES and XRD. The results indicated that the activity and stability of Cu/SiO2 catalyst was increased after adding Zn, Mn, Cr and Fe promoters. Mn promoter was favorable for the dispersion of Cu, Zn, Cr, Fe and enlarged the specific surface area of catalysts. It could be seen that the catalysts prepared by impregnation method had better stability and higher activity than the catalysts prepared by co-precipitation method. The catalysts with small grain size of Cu had higher activity than those with big grain size. Some catalysts showed excellent performances in this reaction.

Ultrathin γ-Al2O3 nanofibers with large specific surface area and their enhanced thermal stability by Si-doping

RSC Advances ◽  
2015 ◽  
Vol 5 (67) ◽  
pp. 54053-54058 ◽  
Author(s):  
Fang Hu ◽  
Xiang Wu ◽  
Yamin Wang ◽  
Xiaoyong Lai
Keyword(s):  
Thermal Stability ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Parallel Flow ◽  
Precipitation Method ◽  
Large Specific Surface Area ◽  
Si Doping ◽  
Co Precipitation

Ultrathin boehmite nanofibers were synthesized via a parallel flow co-precipitation method and then transformed into γ-Al2O3 nanofibers by calcination.

Study on Factors Affecting Properties of Silica

2011 ◽  
Vol 233-235 ◽  
pp. 332-336
Author(s):  
Quan Xiao Liu ◽  
Wen Cai Xu ◽  
Yu Bin Lv ◽  
Jin Li Li
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ph Value ◽  
Precipitation Method ◽  
Drying Methods ◽  
Drying Process ◽  
Factors Affecting ◽  
Base Solution

Silica was prepared by precipitation method in the laboratory, and the factors which affect the performance of silica were evaluated. The results show that the reduction of concentration of base solution and reaction temperature and the increase of pH value could improve the specific surface area of precipitation silica. Specific surface area of silica prepared in laboratory is greater than which was prepared in production line and DBP absorption value and particle size are smaller than the latter. Drying process and drying methods have important influences on performance of precipitation silica. Mechanical pulverization could reduce the particle size of silica slightly and the stacking density obviously.

Facile Synthesis of CeO2/SnO2 N-N Heterostructure

2019 ◽  
Vol 891 ◽  
pp. 200-205 ◽  
Author(s):  
Pimpan Leangtanom ◽  
Nattharinee Charoenrat ◽  
Sukon Phanichphant ◽  
Viruntachar Kruefu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
High Specific Surface Area ◽  
Element Composition ◽  
Precipitation Method ◽  
Average Particle ◽  
Tem Analysis ◽  
Co Precipitation

Cerium oxide and tin oxide nanocomposites (CeO2-SnO2 NCs) were successfully synthesized via a simple co-precipitation method. The structure and properties of the synthesized materials were characterized using several X-ray and electron-based techniques including XRD, FE-SEM, TEM, EDS and BET to unravel the structure, morphology, element composition and specific surface area. The XRD and BET results showed that the NCs have the characteristic crystalline structures of SnO2 and CeO2-SnO2 NCs, and high specific surface area (66.45 and 86.29 m2/g), respectively. Amorphous phase of CeO2 and SnO2 were not found in XRD patterns. EDS analysis confirms the absence of all element composition and the FE-SEM and TEM analysis observed as particles having the clear spherical morphologies with the average particle size of of SnO2 and CeO2-SnO2 NCs was about 13 and 10 nm, respectively.

scholarly journals Photodegradation of Microcystin-LR Using Visible Light-Activated C/N-co-Modified Mesoporous TiO2 Photocatalyst

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1027 ◽  
Author(s):  
Tamer Khedr ◽  
Said El-Sheikh ◽  
Adel Ismail ◽  
Ewa Kowalska ◽  
Detlef Bahnemann
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Hydrothermal Process ◽  
Tio2 Photocatalyst ◽  
X Ray

Microcystin-LR (MC-LR), a potent hepatotoxin produced by the cyanobacteria, is of increasing concern worldwide because of severe and persistent impacts on humans and animals by inhalation and consumption of contaminated waters and food. In this work, MC-LR was removed completely from aqueous solution using visible-light-active C/N-co-modified mesoporous anatase/brookite TiO2 photocatalyst. The co-modified TiO2 nanoparticles were synthesized by a one-pot hydrothermal process, and then calcined at different temperatures (300, 400, and 500 °C). All the obtained TiO2 powders were analyzed by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscope (TEM), specific surface area (SSA) measurements, ultraviolet-visible diffuse reflectance spectra (UV-vis DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and photoluminescence (PL) analysis. It was found that all samples contained mixed-phase TiO2 (anatase and brookite), and the content of brookite decreased with an increase in calcination temperature, as well as the specific surface area and the content of non-metal elements. The effects of initial pH value, the TiO2 content, and MC-LR concentration on the photocatalytic activity were also studied. It was found that the photocatalytic activity of the obtained TiO2 photocatalysts declined with increasing temperature. The complete degradation (100%) of MC-LR (10 mg L−1) was observed within 3 h, using as-synthesized co-modified TiO2 (0.4 g L−1) at pH 4 under visible light. Based on the obtained results, the mechanism of MC-LR degradation has been proposed.

Preparation of Sands Modified by Aluminous Salt and its Adsorption Capability of CD2+

2011 ◽  
Vol 130-134 ◽  
pp. 856-859
Author(s):  
Chun Sheng Ding ◽  
Yang Ping Fu ◽  
Qian Fen Zhu ◽  
Jing Fu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Influencing Factors ◽  
Removal Efficiency ◽  
Specific Surface Area ◽  
Quartz Sand ◽  
Ph Value ◽  
Alkaline Condition ◽  
Initial Concentration ◽  
Adsorption Capability

In this experiment quartz sand was chosen as a carrier to be coated by aluminous salt under alkaline condition, and then the specific surface area was tested, and the adsorption capability and Cd2+ removal influencing factors of modified sand were studied. The investigation results showed that the specific surface area of modified sand was 75.244m2/g which was 9.38 times of that of original sand; the removal efficiency of Cd2+ by aluminous salt modified sand reached 59% contrast to 39% of original sand with pH 7.00. It was also found that the removal efficiency of Cd2+ by the aluminous salt modified sand was reduced with the increase of initial concentration of Cd2+ solution, and was enhanced with the increase of pH value, the Cd2+ removal efficiency was almost 71% with pH 9.0.

Comparative Analysis on Chemical Composition and Charcoal Characterization of Two Miscanthus Species

2011 ◽  
Vol 415-417 ◽  
pp. 1265-1272
Author(s):  
Wen Biao Zhang ◽  
Wen Zhu Li ◽  
Bing Song Zheng
Keyword(s):  
Chemical Composition ◽  
Specific Surface ◽  
Water Content ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ph Value ◽  
Perennial Grass ◽  
Water Extract ◽  
Carbonization Temperature ◽  
Hot Water

Miscanthus is a highly productive, rhizomatous, C4 perennial grass that should be considered as an excellent active carbon precursor. This paper compares the charcoal characterization and chemical composition between M. sinensis and M. floridulus. Species differed in water content, hot water extract, 1% NaOH extract, organic solvent extract, cellulose, lignin and ash. Carbonization temperatures have effects on charcoal yields of Miscanthus, which ranged from 23.5% to 48.0% for M. sinensis and 11.3% to 37.2% for M. floridulus. Water content, charcoal density, pH value, and specific surface area of charcoal characterization varied between two species of Miscanthus. The specific surface area increased with the increase of carbonization temperature. The highest specific surface area of M. sinensis and M. floridulus was 351.74 m2g−1and 352.74 m2g−1, respectively, when the carbonization temperature was 800°C.

Preparing of Silica Aerogel and Adsorption Performance on Nitrobenzene

2012 ◽  
Vol 512-515 ◽  
pp. 1980-1985
Author(s):  
Ya Jun Luo ◽  
Xue Li ◽  
Xiao Li Hu ◽  
Deng Liang He ◽  
Peng Lin
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ph Value ◽  
Adsorption Property ◽  
Infrared Absorption Spectrum ◽  
Nitrobenzene Solution ◽  
Silica Source ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

SiO2aerogel is prepared under normal conditions by taking tetraethyl orthosilicate (TEOS) as the silica source, N-hexane as the displacer, trimethylchlorosilane hexane as the modifier and hydrolysis environment provided by hydrochloric acid and ammonia water. The effect of pH value, time, temperature, initial concentration on the adsorption of nitrobenzene by aerogel has been studied. The results show that the best range of the pH value for adsorption is 10.72. When adsorption time is 100 min, adsorption equilibrium can be reached. The best temperature for adsorption is 40 °C. The adsorption capacity becomes larger with the concentration increasing of the nitrobenzene solution. When the concentration reaches 500 mg/L, the adsorption reaches 32.402 mg/g. The adsorption equation matches Langmuir model. Scanning Electron Microscopes (SEM), infrared absorption spectrum and specific surface area measurements have shown that the adsorption property of SiO2aerogel for the nitrobenzene is related to cellular structure of the aerogel and large specific surface area.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Core Shell ◽  
Adsorption Desorption

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

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