Study on the Synthesis and Properties of Nano-ZnO

2011 ◽  
Vol 694 ◽  
pp. 324-327 ◽  
Author(s):  
Zong Rui Liu ◽  
Jie Hou ◽  
Li Mei Duan ◽  
Ling Xu
Keyword(s):  
Particle Size ◽  
Acetic Acid ◽  
Polyethylene Glycol ◽  
Sol Gel ◽  
Raw Material ◽  
N2 Adsorption ◽  
Nano Zno ◽  
Polyethylene Glycol 4000 ◽  
Dispersion Degree ◽  
Adsorption Desorption

Nano-ZnO was synthesized by sol-gel method using acetic acid zinc and ammonia as raw material and characterized by XRD, SEM, TEM and N2 adsorption-desorption measurements. In addition, the photoluminescence performance of nano-ZnO was analyzed through PL spectra. The particle size and dispersion degree of nano-ZnO could be controlled by adjusting the addition of surfactant polyethylene glycol-4000. The characterization results revealed that the crystallinity and dispersion degree of nano-ZnO were high and the surface area of nano-ZnO was large, when the amount of polyethylene glycol-4000 was 293.44 mg.

Effect of L-Arginine on the Carbon Microsphere Forming under Hydrothermal Carbonization

2019 ◽  
Vol 41 (1) ◽  
pp. 72-72
Author(s):  
Jilei Liang Jilei Liang ◽  
Mengmeng Wu Mengmeng Wu ◽  
Hongmei Cai Hongmei Cai ◽  
Hao Wang Hao Wang ◽  
Hua Huang Hua Huang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Adsorption Capacity ◽  
Surface Property ◽  
Condensation Reaction ◽  
Hydrothermal Carbonization ◽  
Carbon Microspheres ◽  
N2 Adsorption ◽  
Sem Images ◽  
Ft Ir ◽  
Adsorption Desorption

Carbon microspheres (CMs) with a diameter of 5-10 μm have been synthesized by hydrothermal carbonization of starch and L-arginine. The surface property and structure of CMs were examined by FT-IR spectra, N2 adsorption-desorption isotherms and SEM images. These characterizations indicated that the L-arginine does not connect into the CMs but it promotes the starch hydrolysis and polymerization-condensation reaction of intermediate, which accelerates the formation of CMs and improves the yield in shorter time. The surface property of CMs determines adsorption capacity for acetic acid. By contrast, the porosity resulted from the carbonization at 500 and#176;C dominates the adsorption capacity for acetic acid.

Investigation of Interrelation between Particle Size and Phase Transition in the Al2O3-ZrO2 System

2009 ◽  
Vol 6 ◽  
pp. 35-41
Author(s):  
Denis A. Ivanov-Pavlov ◽  
Vladimir G. Konakov ◽  
Elena N. Solovieva ◽  
Viktor M. Ushakov ◽  
Natalia V. Borisova
Keyword(s):  
Phase Transition ◽  
Particle Size ◽  
Sol Gel ◽  
Scanning Calorimetry ◽  
Gel Method ◽  
Sol Gel Method ◽  
Drying Conditions ◽  
Phase Symmetry ◽  
Adsorption Desorption ◽  
Zro2 System

Powder precursors of the Al2O3-ZrO2 system were synthesized by the sol-gel method. Dispersity of the powders depended on synthesis and drying conditions. Differential Scanning Calorimetry, X-Ray diffraction, and method of adsorption–desorption isotherms were used to characterize the interrelations between particle size and phase transition in the Al2O3-ZrO2 system. It was revealed that azeotropic drying under overpressure is quite effective for obtaining well-dispersed powder precursors synthesized by the sol-gel method. In contrast to bulk materials, tetragonal, cubic, and monoclinic phases were found to exist in a wider temperature-composition range. It was shown that the existing phase symmetry in the well-dispersed powders correlates with the crystallite size.

Preparation of Nano-Size PbTiO3 Particles and its Characteristics on the Adsorption of Organic Acids

2007 ◽  
Vol 544-545 ◽  
pp. 797-800
Author(s):  
Kun Ho Song ◽  
Byoung Moon Kim ◽  
Jeong Eun Kim ◽  
Kwang Rae Lee
Keyword(s):  
Particle Size ◽  
Acetic Acid ◽  
Organic Acids ◽  
Formic Acid ◽  
Catalyst Concentration ◽  
Sol Gel ◽  
Experimental Conditions ◽  
Calcination Process ◽  
Processing Variables ◽  
Nano Size

The nano-size PbTiO3 particles were prepared by sol-gel method and the effects of processing variables such as concentration of sol solution, catalyst, concentration of catalyst, calcination temperature and calcination process on particle size of PbTiO3 were analyzed. The condition for preparation of sol solution from the precursor is very critical to the size of PbTiO3 particle. At certain experimental conditions, the particles of 129nm, 213nm and 343nm were obtained. However, the particle size of commercialized PbTiO3 powder was 5㎛(5,000nm). The prepared nano-size PbTiO3 powder adsorbed more acetic acid and formic acid than the commercialized one; 1.5 times for acetic acid and 1.2 times for formic acid. Formic acid was preferentially adsorbed than acetic acid.

scholarly journals Synthesis of Hydroxyapatite and ZnO Nanoparticles via Different Routes and its Comparative Analysis

2016 ◽  
Vol 13 (1) ◽  
pp. 07-13 ◽  
Author(s):  
P. Mahapatra ◽  
Shreya Kumari ◽  
Simran Simran ◽  
Shruti Sharma ◽  
K. Gaurav ◽  
...  
Keyword(s):  
Particle Size ◽  
Acetic Acid ◽  
Comparative Analysis ◽  
Sol Gel ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wurtzite Crystal Structure ◽  
Egg Shells ◽  
Removal Of Metal Ions

Hydroxyapatite (HAp) was prepared from egg shells by various routes using hexane and acetic acid followed by heat treatment. HAp has a wide application in water treatment by removal of metal ions. XRD of the samples showed use of acetic acid followed by high temperature sintering leads to formation crystalline phases of HAp. Strong evidence of CaCO3 in calcite phase was obtained in other samples. Zinc oxide nanoparticles have also been synthesized by different methods such as sol-gel, co- precipitate and green synthesis. The effect of different synthesis methods were investigated using X-Ray Diffraction (XRD). The structural properties of nanoparticles including particle size were calculated from XRD data. The XRD reveals that the prepared ZnO samples were highly crystalline, having wurtzite crystal structure. The comparative analysis shows variations in particle size with different synthesis methods.

scholarly journals Nitrogen-doped-TiO2 nanocatalyst for selective photocatalytic CO2 reduction to fuels in a monolith reactor

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Beenish Tahir ◽  
Muhammad Tahir ◽  
Nor Aishah Saidina Amin
Keyword(s):  
Irradiation Time ◽  
Anatase Phase ◽  
Sol Gel ◽  
Co2 Reduction ◽  
Feed Ratio ◽  
N2 Adsorption ◽  
Doped Tio2 ◽  
Yield Rate ◽  
Ch4 Production ◽  
Adsorption Desorption

In this study, photocatalytic CO2 reduction with H2 over nitrogen (N)-doped TiO2 nanocatalyst in a monolith photoreactor has been investigated. The N-doped TiO2 nanocatalyst was synthesized by sol-gel method, dip-coated over the monolith channels, and characterized by XRD, SEM and N2 adsorption-desorption. Highly crystalline and anatase phase TiO2 was produced in the N-doped TiO2 samples with increased surface area and reduced crystallite size. The N-doped TiO2 nanocatalyst demonstrated excellent photoactivity for selective CO2 reduction to CO in a continuous monolith photoreactor. The 3 wt. % N-doped TiO2 was found to be the most optimal, giving maximum CO yield rate of 56.30 µmole g-catal.-1 h-1 with selectivity of 96.3% at CO2/H2 feed ratio 1 and feed flow rate 20 mL/min. The performance of monolithic N-doped TiO2 nanocatalyst for selective and continuous CO production was 4.7 fold higher than un-doped TiO2. The significantly enhanced TiO2 activity was evidently due to hindered charges recombination rate due to N2 doping. The N-doped TO2 gave prolonged stability for continuous CO and CH4 production over the irradiation time. 

Novel Precipitation Route to Silica Grain

1992 ◽  
Vol 271 ◽  
Author(s):  
Barbara Simms ◽  
Tom Gallo
Keyword(s):  
Particle Size ◽  
Acetic Acid ◽  
Aqueous Ammonia ◽  
Sol Gel ◽  
Average Particle ◽  
Particle Sizes ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Small Particles ◽  
High Degree

ABSTRACTWe describe a novel precipitation route to silica grain that lies in the interface between sol-gel and Stöber-type silica. The use of acetic acid as a catalyst for TEOS hydrolysis provides access to a precipitation window in which partially hydrolyzed TEOS and TEOS monomer, when reacted with aqueous ammonia, combine to form pumice-like silica particles in up to 90% yield as SlO2. Precipitated particles exhibit narrow particle size distributions that may be controlled for average particle sizes from 50µ to 400 µ. SEM micrographs show that the particles are agglomerates of small particles, which is consistent with the high degree of observed macroporosity.

Effects of pH Value and Water Content of Sol on TiO2 Photocatalytic Activity Prepared by SAS

2013 ◽  
Vol 774-776 ◽  
pp. 864-867
Author(s):  
Zai Feng Shi ◽  
Su Min Zhang ◽  
Su Guo
Keyword(s):  
Methylene Blue ◽  
Particle Size ◽  
Photocatalytic Activity ◽  
Citric Acid ◽  
Water Content ◽  
Mass Fraction ◽  
Ph Value ◽  
Sol Gel ◽  
Raw Material ◽  
Effects Of Ph

To investigate the effects of sol pH value and water content on photocatalytic activity of TiO2 prepared with sol-gel auto-igniting synthesis (SAS) method, TiO(NO3)2 was prepared with TiCl4 as raw material and used as precursor of TiO2. By changing sol pH value and water content, different TiO2 powders were prepared and characterized with XRD, SEM and photodegradation of methylene blue (MB). Results indicated that TiO2 presented the highest photocatalytic activity while sol pH value and mass fraction of water were adjusted to 7 and 50% respectively while the mole ratio of n (TiCl4): n (citric acid): n (ammonium nitrate) was fixed as 1: 1: 3. The TiO2 powders were confirmed as loose and porous anatase type with particle size of 15 nm by SEM and XRD.

Preparation and Characterization of RF/SiO2 Hybrid Aerogel by Sol-Gel Method

2006 ◽  
Vol 11-12 ◽  
pp. 619-622 ◽  
Author(s):  
Xiao Hong Chen ◽  
Shuang Xi Yang ◽  
Huai He Song
Keyword(s):  
Raw Materials ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Ethanol Solution ◽  
Raw Material ◽  
Step Method ◽  
Wide Range ◽  
Hybrid Aerogels ◽  
Adsorption Desorption ◽  
Hybrid Aerogel

A novel organic and inorganic hybrid aerogel of RF/SiO2 is synthesized by one-step method of sol-gel polycondensation reaction using resorcinol-formaldehyde and tetramethoxysilane (TMOS) in ethanol solution, followed by supercritical drying with petroleum ether. The influence of the ratio of raw material on the structure and properties of samples was studied by high resolution electron microscope (HREM), nitrogen adsorption-desorption and infrared ray technology (IR). The results showed that the network structures of RF/SiO2 hybrid aerogels were constituted by an intercross framework of RF and SiO2. The hybrid aerogels can be tuned in bulk density from 0.098 g/cm3 to 0.062 g/cm3 according to the ratio of raw materials. The data of nitrogen adsorption-desorption showed that BET specific surface area was changed from 254 cm2/g to 545 cm2/g, and the pore size of aerogels was in the wide range of 2-10 nm. The investigation of IR spectrum analysis exhibited that there were no chemical bonds formed between SiO2 and RF aerogel.

Sign in / Sign up

Export Citation Format

Share Document