Hydrothermal and Thermal Decomposition Synthesis of Hierarchical NiO Microspheres with Mesoporous Structure

2011 ◽  
Vol 239-242 ◽  
pp. 252-258
Author(s):  
Hui Liu ◽  
Guang Jun Li ◽  
Jun Qi Li ◽  
Na Wei ◽  
Zhen Feng Zhu
Keyword(s):  
Thermal Decomposition ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Structural Features ◽  
Mesoporous Alumina ◽  
N2 Adsorption ◽  
Adsorption Desorption ◽  
Adsorptive Properties

A facile method has been developed to synthesis hierarchical nickel oxide with spherical particle morphologies, high surface area of 234 m2/g and narrow pore distribution at 3.25 nm by controlled thermal decomposition of the nickel nitrate hydroxide precursors. The as-obtained products were well characterized by XRD, SEM, TEM (HRTEM), SAED, FTIR and N2 adsorption-desorption measurement. It was shown that the hierarchical NiO microsphere with the diameter about 2.0 μm is composed of hexagonal nanoparticles with mesoporous structure. The prepared mesoporous materials were used as an adsorbent to remove the Congo red pollutant contained in the waste water, and they exhibited more favorable adsorptive properties than the mesoporous alumina powders with same surface area due to its special structural features.

scholarly journals Synthesis and characterization of mesoporous materials with SBA and MCM structure types

Cerâmica ◽  
2019 ◽  
Vol 65 (376) ◽  
pp. 585-591
Author(s):  
R. A. Sacramento ◽  
O. M. S. Cysneiros ◽  
B. J. B. Silva ◽  
A. O. S. Silva
Keyword(s):  
Surface Area ◽  
Mesoporous Materials ◽  
High Surface ◽  
High Surface Area ◽  
Textural Properties ◽  
N2 Adsorption ◽  
Structure Directing Agent ◽  
Type Iv ◽  
Xrd Patterns ◽  
Adsorption Desorption

Abstract Mesoporous materials are promising structures for application in catalysis and adsorption due to high surface area and large pore size. Mesoporous materials were synthesized by the hydrothermal method with novel surfactants, distinct from those observed in the literature, in order to carry out a study of its structure and to obtain materials with better textural properties. The structures synthesized with the surfactants Igepal CO630 and Brij O20 presented the best results of specific surface area, 1074 and 1075 m2.g-1, respectively. The obtained materials were characterized by XRD, TG/DTG, N2 adsorption-desorption, and FTIR techniques. XRD patterns indicated that the highly ordered mesoporous silica structures, such as MCM-41 and MCM-48, using CTMABr as the structure-directing agent and the SBA-15, SBA-16 and other SBA structures using different block copolymers were obtained. Through N2 adsorption-desorption isotherms, it was observed type IV isotherms, attributed to mesoporous materials. The FTIR spectra presented similar behaviors with characteristic vibrational bands of MCM and SBA type materials.

scholarly journals Synthesis of Mesoporous Zn1−xMxAl2O4 Substituted by Co2+ and Ni2+ Ions and Application in the Photodegradation of Rhodamine B

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2150
Author(s):  
Nilson Machado Pontes do Nascimento ◽  
Bárbara Ronara Machado de Lima ◽  
José Roberto Zamian ◽  
Carlos Emmerson Ferreira da Costa ◽  
Luís Adriano Santos do Nascimento ◽  
...  
Keyword(s):  
Surface Area ◽  
Rhodamine B ◽  
Removal Rate ◽  
Spinel Phase ◽  
High Surface ◽  
High Surface Area ◽  
N2 Adsorption ◽  
Energy Dispersion Spectroscopy ◽  
Nickel Ions ◽  
Adsorption Desorption

A new mesoporous Zn1-xMxAl2O4 photocatalyst was prepared using the metal-chitosan complexation method with different degrees of Zn2+ cation substitution with cobalt and nickel ions (M = Co2+ and Ni2+). Characterization using X-ray diffraction (XRD), Infrared absorption spectrometry (FTIR), energy dispersion spectroscopy (EDS), diffuse reflectance spectrometry (DRS), scanning electron miscoscopy (SEM), transmission electron miscroscopy (TEM), N2 adsorption- desorption isotherms using the Barrett-Joyner-Halenda (BJH) method, thermogravimetric analysis (TG) and differential thermal analysis (DTA) confirmed the formation of the spinel phase and high purity for all samples. N2 adsorption/desorption and size pore distribution confirmed the high surface area. The photocatalytic activity of Zn1-xMxAl2O4 and the effect of replacing Zn2+ ions with Ni2+ and Co2+ on the degradation of rhodamine B under ultraviolet light were studied in detail. The sample containing 0.1 mol of cobalt had the highest removal rate reaching 83%, favored by surface area and material bandgap (109 m2 g−1 and 2.19 eV, respectively).

Development of α-Fe2O3 as Adsorbent and its Effect on CO2 Capture

2016 ◽  
Vol 840 ◽  
pp. 421-426 ◽  
Author(s):  
Azizul Hakim ◽  
Tengku Sharifah Marliza ◽  
Maratun Najiha Abu Tahari ◽  
Muhammad Rahimi Yusop ◽  
Mohamed Wahab Mohamed Hisham ◽  
...  
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Co2 Adsorption ◽  
High Surface ◽  
High Surface Area ◽  
N2 Adsorption ◽  
Mixing Method ◽  
Desorption Isotherms ◽  
Adsorption Desorption

Iron oxide (α-Fe2O3) as adsorbent was no longer new in CO2 adsorption studies. However, its contributions in the industry still in limited wherein lack of convincing results of quantifying of adsorbed CO2. This work presents an analysis for α-Fe2O3 was prepared by simple mixing method with identified the adsorption capacity that applied in CO2 capture. The synthesized α-Fe2O3 from different concentrations of precursor were analyzed using XRD, N2 adsorption-desorption isotherms with BET and BJH method, TEM, FTIR, CO2 adsorption at 298 K, CO2-TPD and TGA-DTG. It was noted that 2M concentration of precursor (s2M) with highest crystallite peaks shows highest surface area among all samples which indicative of well generated pores. The different concentration of precursor was found generated more porosity rather than particle size according to TEM micrograph. The sphere shape crystallite particle with high surface area (50.5 m2/g) and porosity were desirable properties in CO2 adsorption. Consequently, physically adsorbed CO2 with adsorption at 298 K was highest with adsorption capacity of at 17.0 mgCO2/gadsorbent. Finally, chemically adsorbed CO2 was successfully identified from CO2–TPD analysis with adsorption capacity of 0.19 mgCO2/gadsorbent and 1.31 mgCO2/gadsorbent at maximum desorption temperature of 375 °C and 749 °C respectively.

scholarly journals Synthesis of Bi2O3 Nanosheets and Photocatalysis for Rhodamine B

2019 ◽  
Vol 26 (1) ◽  
pp. 20-24
Author(s):  
Wenwen ZHANG ◽  
Shaomin GAO ◽  
Donghui CHEN
Keyword(s):  
Surface Area ◽  
Rhodamine B ◽  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
High Surface ◽  
High Surface Area ◽  
N2 Adsorption ◽  
Simple Method ◽  
Adsorption Desorption ◽  
Liquid Precipitation

Bi2O3 nanosheets (NSB) photocatalyst was fabricated via a very simple method of liquid precipitation. The as obtained products were characterized by SEM, N2 adsorption-desorption, XRD and UV-vis diffuse reflectance spectra. The results showed that NSB catalyst can beconsidered as set of nanosheets with an average thickness of 110 nm. NSB photocatalyst exhibited high surface area of 33.21 m2/g and high purity. In addition, NSB catalyst displayed excellent photocatalytic performance for the dye of rhodamine B (Rh B) under visible light due to the structure of sheet and high surface area.

Texture Evaluation of Sol-Gel Derived Mesoporous Bioactive Glass

2013 ◽  
Vol 284-287 ◽  
pp. 230-234
Author(s):  
Yu Jen Chou ◽  
Chi Jen Shih ◽  
Shao Ju Shih
Keyword(s):  
Surface Area ◽  
Calcination Temperature ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Bioactive Glasses ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Adsorption Desorption

Recent years mesoporous bioactive glasses (MBGs) have become important biomaterials because of their high surface area and the superior bioactivity. Various studies have reported that when MBGs implanted in a human body, hydroxyl apatite layers, constituting the main inorganic components of human bones, will form on the MBG surfaces to increase the bioactivity. Therefore, MBGs have been widely applied in the fields of tissue regeneration and drug delivery. The sol-gel process has replaced the conventional glasses process for MBG synthesis because of the advantages of low contamination, chemical flexibility and lower calcination temperature. In the sol-gel process, several types of surfactants were mixed with MBG precursor solutions to generate micelle structures. Afterwards, these micelles decompose to form porous structures after calcination. Although calcination is significant for contamination, crystalline and surface area in MBG, to the best of the authors’ knowledge, only few systematic studies related to calcination were reported. This study correlated the calcination parameters and the microstructure of MBGs. Microstructure evaluation was characterized by transmission electron microscopy and nitrogen adsorption/desorption. The experimental results show that the surface area and the pore size of MBGs decreased with the increasing of the calcination temperature, and decreased dramatically at 800°C due to the formation of crystalline phases.

Hard-templating synthesis and enhanced photocatalysis of mesoporous titanium dioxides nanoparticles

2018 ◽  
Vol 11 (04) ◽  
pp. 1850077 ◽  
Author(s):  
K. L. Jin ◽  
X. J. Chen ◽  
J. C. Xu ◽  
Y. S. Huang ◽  
Y. B. Han ◽  
...  
Keyword(s):  
Surface Area ◽  
Anatase Phase ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Photocatalytic Decomposition ◽  
Titanium Dioxides ◽  
Decomposition Efficiency ◽  
Templating Synthesis ◽  
Mb Adsorption

Mesoporous titanium dioxides nanoparticles (TiO2 NPs) were synthesized using activated carbon (AC) as templates after the decomposition of AC. All results indicated that TiO2 NPs with the small grain size presented the anatase phase structure. Mesoporous TiO2 NPs showed the high surface area and the surface area decreased with the TiO2 content. The removal of methylene blue (MB) indicated that the photocatalytic decomposition efficiency of mesoporous TiO2 NPs increased up to 92% for three-times doping with the TiO2 content, and then decreased. This should be attributed to the synergistic effect from the MB adsorption of mesoporous-structure and the photocatalysis of TiO2 NPs. Therefore, the higher MB concentration near TiO2 NPs from the mesoporous-structure increased the touch chance and the MB photocatalytic decomposition was promoted greatly.

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