Preparation and Characterization of Hierarchically Porous SiO2@C@MnO2 Monoliths

2018 ◽  
Vol 768 ◽  
pp. 224-230
Author(s):  
Dao Yan Feng ◽  
Yu Xiao Li ◽  
Hui Yang ◽  
Xing Zhong Guo
Keyword(s):  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
Porous Silica ◽  
Internal Surface ◽  
Inert Atmosphere ◽  
Sem Images ◽  
Xps Spectra ◽  
Hierarchical Porous ◽  
Xrd Patterns ◽  
Reported Data

Hierarchical porous SiO2@C@MnO2monoliths have been fabricated by two step approaches: Elemental carbon was covered the internal surface of porous silica monoliths with impregnation and carbonized in inert atmosphere, and MnO2was directly grown on the skeleton of SiO2@C accompanied by redox reaction between C and KMnO4. The effects of glucose and KMnO4concentrations, and hydrothermal reaction on the morphology of MnO2particles on the surface of SiO2monoliths were investigated in detail. The results showed that the optimal factors of reaction condition involved 0.08 mol·L-1glucose solution, 0.03 mol·L-1KMnO4solution and the reaction time of 5 h. SEM images and BET results indicated that the macroporous structure of the as-prepared material was preserved after modification, while the specific surface area and pore volume decreased with increasing amount of MnO2to some degree. The XPS spectra of SiO2@C@MnO2is in good agreement with reported data in MnO2. The crystal phase of MnO2was α-MnO2after thermal treatment at the temperature of 600 °C from the XRD patterns. Three-dimensional porous well-defined morphological SiO2@C@MnO2be promising materials for the catalytic elimination of air pollutants since large quantities can be obtained from porous structure combined with α-MnO2equipped with high active performance.

Mechanically Strong and Hierarchical Porous Silica Ceramics via Gelcasting-Lyophilization

2016 ◽  
Vol 697 ◽  
pp. 414-418
Author(s):  
Wei Wan ◽  
Jian Yang ◽  
Yong Bao Feng ◽  
Tai Qiu
Keyword(s):  
Raw Materials ◽  
Aqueous Suspension ◽  
Three Dimensional ◽  
Porous Silica ◽  
Hierarchical Porous ◽  
Exhaust Fumes ◽  
Materials Used ◽  
Gelcasting Process ◽  
Hierarchical Pore ◽  
Highly Porous

Highly porous silica ceramics were prepared by in-situ gelation of an aqueous suspension with well dispersed silica particles and N’N-dimethylacrylamide (DMAA) monomer, followed by lyophilization and pressureless sintering. The gelcasting process was imparted by polymerization of DMAA. The silica raw materials used in this experiment are the dusts collected from the exhaust fumes of silicon industry. The as-obtained porous silica ceramics had three-dimensional and hierarchical pore structure and the porosity ranged from 75 to 88 % as the sintering temperature varied from 850 to 1050 °C. In addition, the porous silica ceramics appeared to have strong mechanical strength. Compressive strength of the porous silica ceramics was as high as 3.2 MPa even when the porosity was nearly 80%. The gelcasting-lyophilization method was proved to be a novel and promising route for the preparation of highly porous and mechanically strong materials.

Enhanced Performance of Ultrafiltration Membrane with Powdered Zeolite Addition for Secondary Effluent Treatment

2013 ◽  
Vol 838-841 ◽  
pp. 2712-2716
Author(s):  
Yong Tu ◽  
Yong Gang Bai ◽  
Yong Chen ◽  
Wei Jing Liu ◽  
Jun Xu ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Fluorescence Spectra ◽  
Municipal Wastewater ◽  
Three Dimensional ◽  
Treatment Plant ◽  
Ultrafiltration Membrane ◽  
Effluent Treatment ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Sem Images

The research on ultrafiltration membrane assisted by powdered zeolite for the treatment of secondary effluent from a municipal wastewater treatment plant was studied. The results show that membrane fouling rate is reduced by pre-coating the ultrafiltration membrane with powdered zeolite, and the treatment performance of secondary effluent is enhanced. UV-vis, three-dimensional excitation emission matrix (3D-EEM) fluorescence spectra and scanning electron microscopy (SEM) images for ultrafiltration were also discussed.

Preparation and Characterization of NTC NiMn2O4-La1-xCaxMnO3 (0≤x≤0.3) Composite Ceramics

2013 ◽  
Vol 716 ◽  
pp. 78-83 ◽  
Author(s):  
Hui Min Zhang ◽  
Fang Guan ◽  
Ai Min Chang ◽  
Li Jun Zhao
Keyword(s):  
Electrical Resistivity ◽  
Perovskite Structure ◽  
Spinel Structure ◽  
Thermal Constant ◽  
Inrush Current ◽  
Composite Ceramics ◽  
Sem Images ◽  
Conventional Solid State Reaction ◽  
Different Temperatures ◽  
Xrd Patterns

Composite ceramics made of spinel structure NiMn2O4 and CaO-doped perovskite structure LaMnO3 were prepared by a conventional solid state reaction and sintered at different temperatures. The XRD patterns have shown that the major phases presented in the sintered samples are NiMn2O4 compounds with the spinel structure, La1-xCaxMnO3 with the perovskite structure and NiO with a monoclinic structure. SEM images show that the density and grain size of the composite ceramics increases with sintered temperature increasing. The electrical resistivity of the composite ceramics at 25°C is found to change significantly depending on the CaO content, while the thermal constant B is still reasonably large in the range of 2400 to 3000 K. For the composition x = 0.1, the composite with a low electrical resistivity (ρ25°C=4.46Ω·cm) and moderate B value (B25/50=2762K) was obtained. These composites could be applied as potential candidates for NTC thermistors in the suppression of the inrush current.

Eco-fabrication of hierarchical porous silica monoliths by ice-templating of rice husk ash

2017 ◽  
Vol 19 (1) ◽  
pp. 188-195 ◽  
Author(s):  
Amin Bahrami ◽  
Ulla Simon ◽  
Niloofar Soltani ◽  
Sara Zavareh ◽  
Johannes Schmidt ◽  
...  
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Porous Silica ◽  
Synthesis Process ◽  
Sustainable Chemistry ◽  
Silica Monoliths ◽  
Hierarchical Porous ◽  
Ice Templating

In this study, within a sustainable chemistry approach, a clean and eco-friendly synthesis process of silica monoliths compatible with environmental limitations is developed.

Synthesis, Characterization and Properties of PANI/(La-Nd Doped BaFe12O19) Composites

2017 ◽  
Vol 727 ◽  
pp. 327-334
Author(s):  
Yan Wang ◽  
Jun Wang ◽  
Xiao Fei Zhang ◽  
Ya Qing Liu
Keyword(s):  
Sol Gel ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Structure Morphology ◽  
Xrd Patterns ◽  
Hexagonal Platelet ◽  
Peak Value ◽  
Properties Of Composites

La-Nd co-doped barium hexaferrites, Ba0.7(LamNdn)0.3Fe12O19 (D-BaM), were successfully prepared by sol-gel method. PANI / D-BaM composites were synthesized by in-situ polymerization in solution. The structure, morphology and properties of samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), four-probe conductivity tester and vector network analyzer. The XRD patterns showed that the crystal structure of all the samples exist as M-type phases. The SEM images revealed that the particles presented a hexagonal platelet-like morphology. The magnetic properties could be improved by substitutions of La and Nd ions. The saturation magnetization (Ms) and coercive force (Hc) increased with the change of La / Nd ratio to the maximum at La / Nd = 3:1. The doped particles have also been embedded in conductive PANI to prepare electromagnetic materials, and the conductivity kept on the order of 10-2. The microwave absorbing properties of composites at 30 MHz-6 GHz improved obviously, the peak value of reflection loss could reach-7.5 dB.

Preparation of catalyst as Au doped Mn1Co9Ox/ceramic system for total oxidation of CO

2021 ◽  
Vol 10 (4) ◽  
pp. 39-45
Author(s):  
Phuong Pham Thi Mai ◽  
Hoan Nguyen Quoc ◽  
Quan Do Quoc ◽  
Hung Nguyen Thanh
Keyword(s):  
Sol Gel ◽  
Active Phase ◽  
Catalyst System ◽  
Oxidation Of Co ◽  
Sem Images ◽  
Total Oxidation ◽  
Wet Impregnation ◽  
Modern Analysis ◽  
Catalyst Powder ◽  
Xrd Patterns

In this paper, the Au doped Mn1Co9Ox was investigated for total oxidation of CO. The sol-gel method was applied to prepare this catalyst and some modern analysis methods as XRD, EPR, TPx, SEM were utilized to characterize its properties. The XRD patterns showed only Co3O4 phase without any peaks belonging to Mn or Au. However, the presence of Au and Mn was confirmed by EPR and O2-TPD results. With the aim to further apply catalyst in reality, the Au doped Mn1Co9Ox was deposited on ceramic by sol-gel, wet impregnation. The SEM images displayed the successful coating of active phase on substrate. However, the complete catalyst system didn’t have the high activity in total CO oxidation like the catalyst powder because of large agglomerations on coatings.

Fabrication of nitrogen-doped hierarchical porous carbons from Sargassum as advanced electrode materials for supercapacitors

2021 ◽  
Author(s):  
Feiqiang Guo ◽  
Yinbo Zhan ◽  
Xiaopeng Jia ◽  
Huiming Zhou ◽  
Shuang Liang ◽  
...  
Keyword(s):  
High Performance ◽  
Nitrogen Doping ◽  
Electrode Materials ◽  
Three Dimensional ◽  
Koh Activation ◽  
Porous Carbons ◽  
Nitrogen Doped ◽  
Novel Approach ◽  
Hierarchical Porous ◽  
Hierarchical Porous Carbons

Using Sargassum as the precursor, a novel approach was developed to synthesize three-dimensional porous carbons as high-performance electrode materials for supercapacitors via KOH activation and subsequent nitrogen-doping employing melamine as...

Synthesis of hierarchical porous CuO Nanowire@NiCo-layered double hydroxide core-shell structured nanoarrays on copper foam for high-performance supercapacitors

2017 ◽  
Author(s):  
Guo Hengzhi ◽  
Ben Qing ◽  
Shuxing Wu ◽  
Oscar K.S. Hui ◽  
Zalnezhad Erfan
Keyword(s):  
Layered Double Hydroxide ◽  
High Performance ◽  
Three Dimensional ◽  
Core Shell ◽  
Deposition Technique ◽  
Cuo Nanowires ◽  
Copper Foam ◽  
Hierarchical Porous ◽  
Cuo Nanowire ◽  
Double Hydroxide

In this work, a facile potentiostatic deposition technique was used to fabricate a three-dimensional (3D) core-shell structured nanoarray composed of hierarchical porous CuO nanowires@NiCo layered double hydroxide nanosheets (CuO NWAs@NiCo-LDH)...

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