scholarly journals Preparation and Characterization of Zeolite/TiO2 Cement-Based Composites with Excellent Photocatalytic Performance

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2485 ◽  
Author(s):  
Gang Liao ◽  
Wu Yao ◽  
Junqing Zuo
Keyword(s):  
Active Sites ◽  
Photocatalytic Performance ◽  
Energy Dispersive Spectrometer ◽  
Photocatalytic Efficiency ◽  
Adsorption Volume ◽  
Tio2 Particles ◽  
Bet Specific Surface Area ◽  
Infrared Spectrometer ◽  
Photocatalytic Reactions

A zeolite/TiO2 composite (ZTC) was applied to prepare a high-quality photocatalytic cement-based material (PCM). The acetone degradation experiment and micro measurements including XRD(X-Ray Diffractometer), SEM-EDS(Scanning Electron Microscope-Energy Dispersive Spectrometer), BET(BET Specific Surface Area Tester), FTIR(Fourier Transform Infrared Spectrometer) were conducted to characterize the photocatalytic efficiency and physicochemical properties of PCM, respectively. Results show that TiO2 particles disperse on the surface of a PCM homogeneously and provide abundant active sites for photocatalytic reactions. Compared to a normal photocatalytic cement-based material (NPCM), the TiO2 content of a PCM is lower and its photocatalytic efficiency is higher. The ZTC frees TiO2 particles from the impacts of cement hydration products and increases the adsorption volume of acetone. The photocatalytic performance of the PCM was stable after repeated tests. Using the ZTC as a photocatalyst has a prominent effect on the photocatalytic performance of the PCM.

Preparation and Characterization of TiO2/Coconut-Activated Carbon Photocatalytic Materials

2014 ◽  
Vol 1015 ◽  
pp. 667-670
Author(s):  
Chuan Bao Zhao ◽  
Dong Mei Shi ◽  
Bo Tao Lin ◽  
Yan Qiang Jia
Keyword(s):  
Composite Material ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Photocatalytic Performance ◽  
Photocatalytic Efficiency ◽  
Use Of Technology ◽  
Photocatalytic Materials

Using Ti (OC4H9)4 as the precursor,and GAC as carrier, making use of technology of hydrolyzation and natural assembling,TiO2/GAC composite material was preparated at the lower temperature.The characterization of obtained TiO2 /Coconut-Activated Carbon’scrystal structure and appearance by XRD and SEM.The adsorption capacity and photocatalytic performance on phenol were measured.Results show that TiO2/GAC surface was well-distributed and remains a little interspace.A nanocrystal TiO2 aerogel size is without 30nm.The sample shows lower adsorption compared to GAC.But photocatalytic efficiency was higher than GAC under the exposure of the sunlight or the violet.

Preparation, Characterization of Fe3O4/TiO2/CuO Nanohybrid and its Potential Performance for Chromium Removal from Aqueous Solution

2015 ◽  
Vol 827 ◽  
pp. 49-55 ◽  
Author(s):  
Sarah A. Arifin ◽  
Shofianina Jalaludin ◽  
Rosari Saleh
Keyword(s):  
Aqueous Solution ◽  
Hexavalent Chromium ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Visible Region ◽  
Chromium Removal ◽  
Photocatalytic Efficiency ◽  
Complicated Process ◽  
Nanohybrid Materials

Fe3O4/TiO2and Fe3O4/CuO nanohybrid nanohybrid materials have attracted widespread attention due to their scientific and technological importance as photocatalyst. Complicated process is usually used to synthesize these nanohybrid. In this study, we demonstrated a simple low-temperature sol-gel method to prepare Fe3O4/TiO2/CuO nanohybrid as photocatalyst. Hexavalent chromium was used as a model pollutant to evaluate their photocatalytic activity. The results of the photoreduction of hexavalent chromium in aqueous solution indicated that with the incorporation of CuO content in Fe3O4/TiO2nanohybrid increasing the photocatalytic performance in ultraviolet and visible region. Moreover, it is found that hydroxyl radical has an important role in photocatalytic efficiency.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

A Pyridinic Fe-N4 Macrocycle Effectively Models the Active Sites in Fe/N-Doped Carbon Electrocatalysts

2020 ◽  
Author(s):  
Travis Marshall-Roth ◽  
Nicole J. Libretto ◽  
Alexandra T. Wrobel ◽  
Kevin Anderton ◽  
Nathan D. Ricke ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Active Sites ◽  
Catalytic Properties ◽  
Reduction Reaction ◽  
Iron Phthalocyanine ◽  
Electrochemical Studies ◽  
Onset Potential ◽  
Nitrogen Doped Carbon ◽  
Iron Active Sites

Iron- and nitrogen-doped carbon (Fe-N-C) materials are leading candidates to replace platinum in fuel cells, but their active site structures are poorly understood. A leading postulate is that iron active sites in this class of materials exist in an Fe-N<sub>4</sub> pyridinic ligation environment. Yet, molecular Fe-based catalysts for the oxygen reduction reaction (ORR) generally feature pyrrolic coordination and pyridinic Fe-N<sub>4</sub> catalysts are, to the best of our knowledge, non-existent. We report the synthesis and characterization of a molecular pyridinic hexaazacyclophane macrocycle, (phen<sub>2</sub>N<sub>2</sub>)Fe, and compare its spectroscopic, electrochemical, and catalytic properties for oxygen reduction to a prototypical Fe-N-C material, as well as iron phthalocyanine, (Pc)Fe, and iron octaethylporphyrin, (OEP)Fe, prototypical pyrrolic iron macrocycles. N 1s XPS signatures for coordinated N atoms in (phen<sub>2</sub>N<sub>2</sub>)Fe are positively shifted relative to (Pc)Fe and (OEP)Fe, and overlay with those of Fe-N-C. Likewise, spectroscopic XAS signatures of (phen<sub>2</sub>N<sub>2</sub>)Fe are distinct from those of both (Pc)Fe and (OEP)Fe, and are remarkably similar to those of Fe-N-C with compressed Fe–N bond lengths of 1.97 Å in (phen<sub>2</sub>N<sub>2</sub>)Fe that are close to the average 1.94 Å length in Fe-N-C. Electrochemical studies establish that both (Pc)Fe and (phen<sub>2</sub>N<sub>2</sub>)Fe have relatively high Fe(III/II) potentials at ~0.6 V, ~300 mV positive of (OEP)Fe. The ORR onset potential is found to directly correlate with the Fe(III/II) potential leading to a ~300 mV positive shift in the onset of ORR for (Pc)Fe and (phen<sub>2</sub>N<sub>2</sub>)Fe relative to (OEP)Fe. Consequently, the ORR onset for (phen<sub>2</sub>N<sub>2</sub>)Fe and (Pc)Fe is within 150 mV of Fe-N-C. Unlike (OEP)Fe and (Pc)Fe, (phen<sub>2</sub>N<sub>2</sub>)Fe displays excellent selectivity for 4-electron ORR with <4% maximum H<sub>2</sub>O<sub>2</sub> production, comparable to Fe-N-C materials. The aggregate spectroscopic and electrochemical data establish (phen<sub>2</sub>N<sub>2</sub>)Fe as a pyridinic iron macrocycle that effectively models Fe-N-C active sites, thereby providing a rich molecular platform for understanding this important class of catalytic materials.<p><b></b></p>

scholarly journals Physical and mechanical properties of rubberwood (Hevea brasiliensis) dyed with Lasiodiplodia theobromae

2019 ◽  
Vol 65 (1) ◽  
Author(s):  
Boshi Zhao ◽  
Zhiming Yu ◽  
Yang Zhang ◽  
Chusheng Qi
Keyword(s):  
Mass Loss ◽  
Water Absorption ◽  
Hevea Brasiliensis ◽  
Ph Value ◽  
Energy Dispersive Spectrometer ◽  
Physical And Mechanical Properties ◽  
Blue Staining ◽  
Loss Ratio ◽  
Lasiodiplodia Theobromae ◽  
Infrared Spectrometer

AbstractBlue staining on rubberwood (Hevea brasiliensis) is a common kind of defect. There currently exists much research focused on the prevention and control of blue staining. However, little research has been concentrated on the utilization of blue staining for green dyeing. The research conveyed in this paper primarily used Lasiodiplodia theobromae to dye rubberwood, and used scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR) to analyze the commission internationale eclairage (CIE) L*a*b* value of color, the contact angle, the pH value, 24-h water absorption, mass loss ratio, and compressive strength in increments between 5 and 40 days. The results found that the color of rubberwood became darker and more uniform, and that the surface dyed with fungi can reach a super-hydrophobic state. With the increase of time, the pH value of rubberwood changed from acidic to alkaline. Furthermore, hyphae entered the wood mainly through vessels for their large pore diameter, and reduced water absorption. Mass loss ratio increased gradually between 5 and 40 days. The research in this paper concludes that the microorganism was an effective method of wood dyeing, and lays a foundation for further research.

Defect engineering and characterization of active sites for efficient electrocatalysis

Nanoscale ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 3327-3345
Author(s):  
Xuecheng Yan ◽  
Linzhou Zhuang ◽  
Zhonghua Zhu ◽  
Xiangdong Yao
Keyword(s):  
Transition Metal ◽  
Active Sites ◽  
Defect Engineering ◽  
Metal Free

This review highlights recent advancements in defect engineering and characterization of both metal-free carbons and transition metal-based electrocatalysts.

Visible-light-responsive lanthanide coordination polymers for highly efficient photocatalytic aerobic oxidation of amines and thiols

2021 ◽  
Author(s):  
Zhifen Guo ◽  
Xin Liu ◽  
Yan Che ◽  
Hongzhu Xing ◽  
Peng Chen
Keyword(s):  
Visible Light ◽  
Molecular Oxygen ◽  
Coordination Polymers ◽  
Aerobic Oxidation ◽  
Synthesis And Characterization ◽  
Lanthanide Coordination Polymers ◽  
Highly Efficient ◽  
Photocatalytic Reactions ◽  
Energy Issues

Development of visible-light-induced photocatalytic reactions using molecular oxygen as terminal oxidant is intriguing in view of the current environmental and energy issues. We report herein the synthesis and characterization of...

Synthesis and Characterization of Hematite Nanoparticles as Active Photocatalyst for Water Splitting Application

2013 ◽  
Vol 594-595 ◽  
pp. 73-77 ◽  
Author(s):  
Sze Mei Chin ◽  
Suriati Sufian ◽  
Jeefferie Abd Razak
Keyword(s):  
Surface Area ◽  
Water Splitting ◽  
Combustion Method ◽  
Hydrogen Gas ◽  
Bet Surface Area ◽  
Synthesis And Characterization ◽  
Hematite Nanoparticles ◽  
X Ray ◽  
Bet Specific Surface Area

This paper highlights on the hydrogen production through photocatalytic activity by using hematite nanoparticles synthesized from self-combustion method based on different stirring period. The morphologies and microstructures of the nanostructures were determined using Field-Emission Scanning Electron Microscope (FESEM), X-Ray Diffractometer (XRD) and Particle Size Analyser (PSA). Besides that, surface area analyser was used to determine the BET surface area of the hematite samples. The hematite nanocatalyst as-synthesized are proven to be rhombohedral crystalline hematite (α-Fe2O3) with particle diameters ranging from 60-140 nm. The BET specific surface area of hematite samples increased from 5.437 to 7.6425 m2/g with increasing stirring period from 1 to 4 weeks. This caused the amount of hydrogen gas produced from photocatalytic water splitting to increase as well.

Diffuse Reflectance FT-IR Characterization of Active Sites under Reaction Conditions: The Production of Oxygenates in the CO/H2 Reaction

1994 ◽  
Vol 48 (10) ◽  
pp. 1208-1212 ◽  
Author(s):  
J. J. Benítez ◽  
I. Carrizosa ◽  
J. A. Odriozola
Keyword(s):  
Infrared Spectra ◽  
Active Sites ◽  
Diffuse Reflectance ◽  
Reaction Conditions ◽  
In Situ Drifts ◽  
Ft Ir

The reactivity of a Lu2O3-promoted Rh/Al2O3 catalyst in the CO/H2 reaction is reported. Methane, heavier hydrocarbons, methanol, and ethanol are obtained. In situ DRIFTS has been employed to record the infrared spectra under the actual reaction conditions. The structure of the observed COads DRIFTS bands has been resolved into its components. The production of oxygenates (methanol and ethanol) has been correlated with the results of the deconvolution calculation. Specific sites for the production of methanol and ethanol in the CO/H2 reaction over a Rh,Lu2O3/Al2O3 catalyst are proposed.

Preparation and Characterization of Zn-Containing Hydroxyapatite/TiO2 Composite Coatings on Ti Alloys

2011 ◽  
Vol 685 ◽  
pp. 367-370 ◽  
Author(s):  
Min Qi ◽  
Da Yi Yang ◽  
Jing Ying Zhang ◽  
Hong Jun Ai
Keyword(s):  
Adhesion Strength ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Zn Content ◽  
Micro Arc Oxidation ◽  
Gel Technique ◽  
Bacteria Resistance

In order to improve the osteoblast growth and bacteria resistance, Zn-containing hydroxyapatite (Zn-HA) and titanium oxide (TiO2) composite coatings were prepared to improve binding between coating and Ti substrate. TiO2 film was prepared on the surface of Ti by micro-arc oxidation (MAO) and Zn-HA coating was deposited on TiO2 using sol–gel technique. Phase structure, composition and microstructure of the surface coatings were analyzed by X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS), respectively. The adhesion strength between the coatings with different Zn content was measured by tensile testing. The results showed that there was no significant influence of Zn content on adhesion strength between coating and Ti substrate.

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