Pt Nanocluster Co-Catalysts for Photocatalytic Water Splitting

Degussa P25 is a benchmark form of TiO2 used worldwide in photocatalysis studies. Currently no such benchmark exists for co-catalysts, which are essential for many photocatalytic reactions. Here, we present the preparation of Pt nanocluster co-catalysts on TiO2 using an unmodified commercial source and equipment that is commonly available. Transmission electron microscopy reveals that the procedure produces TiO2 decorated with Pt atom and nanoclusters (1-5 atoms). Optical reflectance and X-ray diffraction measurements show that the procedure does not affect the TiO2 polymorph or UV-Vis absorbance. Gas phase photocatalytic splitting of heavy water (D2O) shows that the Pt nanocluster decorated TiO2 outperforms Pt nanoparticle (produced by photodeposition) decorated TiO2 in D2 production. Pt nanoclusters, produced directly from a commercial source, with high co-catalyst activity are prime candidates to be used in benchmark photocatalytic reactions.

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Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽

10.3390/cryst11050456 ◽

2021 ◽

Vol 11 (5) ◽

pp. 456

Author(s):

Fahad A. Alharthi ◽

Hamdah S. Alanazi ◽

Amjad Abdullah Alsyahi ◽

Naushad Ahmad

Keyword(s):

Electron Microscopy ◽

Hydrothermal Synthesis ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Structure Morphology ◽

Photocatalytic Activities ◽

Ft Ir ◽

Photocatalytic Reactions ◽

Cobalt Tungstate

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

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Solvothermal Synthesis of Novel 3D Peony-Like TiO2 Microstructures and its Enhanced Photocatalytic Activity

NANO ◽

10.1142/s179329201850056x ◽

2018 ◽

Vol 13 (05) ◽

pp. 1850056 ◽

Cited By ~ 1

Author(s):

Yugan He ◽

Qi Yan ◽

Xiaoyu Chang ◽

Meiying Zhu ◽

Weiwei Wang ◽

...

Keyword(s):

Electron Microscopy ◽

Reaction Time ◽

Uv Light ◽

X Ray Diffraction ◽

Reaction Parameters ◽

X Ray ◽

Uv Light Irradiation ◽

Transmission Electron ◽

Irradiation Power ◽

Degussa P25

A TiO2 photocatalyst with peony-like microstructures and a large percentage of exposed {001} facets was synthesized using a facile solvethermal method. The peony-like TiO2 was obtained using HF as a capping agent, TiCl4 as the precursor and ethanol as the solvothermal agent. The parameters which influence the mophology and formation mechanism of the products including the HF concentration, the reaction time and temperature and the solvothermal solvent, were investigated. The samples were characterized using field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and N2 adsorption and desorption analysis. As the reaction time or reaction temperature increased, the morphology TiO2 changed from hexagonally assembled microspheres to peony-like microflowers which were composed of stacks of ultrathin nanosheets. The other reaction parameters also play a crucial role in the formation of the TiO2 microstuctures. Photocatalytic experiments showed that the synthesized TiO2 outperformed Degussa P25 in the photodegradation of methelene blue under a very weak UV light irradiation (power: 8[Formula: see text]W, light intensity: 0.4[Formula: see text]mW[Formula: see text]cm[Formula: see text]).

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Preparation of Mesoporous Silica-Supported Palladium Catalysts for Biofuel Upgrade

Journal of Nanotechnology ◽

10.1155/2012/309093 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Ling Fei ◽

Harvind Kumar Reddy ◽

Joshua Hill ◽

Qianglu Lin ◽

Bin Yuan ◽

...

Keyword(s):

Electron Microscopy ◽

Mesoporous Silica ◽

Palladium Catalysts ◽

Methyl Esters ◽

Catalyst Activity ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Cnts Surface ◽

Supported Palladium

We report the preparation of two hydrocracking catalysts Pd/CoMoO4/silica and Pd/CNTs/CoMoO4/silica (CNTs, carbon nanotubes). The structure, morphologies, composition, and thermal stability of catalysts were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), and thermogravimetric analysis (TGA). The catalyst activity was measured in a Parr reactor with camelina fatty acid methyl esters (FAMEs) as the feed. The analysis shows that the palladium nanoparticles have been incorporated onto mesoporous silica in Pd/CoMoO4/silica or on the CNTs surface in Pd/CNTs/CoMoO4/silica catalysts. The different combinations of metals and supports have selective control cracking on heavy hydrocarbons.

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Titanate Nanotubes as Futuristic Catalyst Support Material

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.l9549.10101221 ◽

2021 ◽

Vol 10 (12) ◽

pp. 24-27

Author(s):

Dr. Lucky Sikhwivhilu ◽

◽

Dr. Venkataraman Vishwanathan ◽

Keyword(s):

Surface Composition ◽

Ageing Time ◽

Catalyst Support ◽

Titanate Nanotubes ◽

X Ray Diffraction ◽

Time Intervals ◽

X Ray ◽

Transmission Electron ◽

Base Solution ◽

Degussa P25

Titanate Nanotubes (TNT) were synthesized by aging commercial titanium dioxide (TiO2 - Degussa P25) with an alkali (KOH) solution at different time intervals. The prepared materials were investigated for their surface composition and textural behaviour by X-ray powder diffraction (XRD), Raman spectroscopy, Gas (N2 and CO2) adsorption measurements, and Transmission electron microscopy (TEM). The X-ray diffraction spectra revealed the decrease in the crystalline nature of the materials decreased by exposing them for a longer duration in the base solution. Raman spectra results showed that ageing time affected the structural properties. The specific surface area and the pore size of the newly synthesised materials were affected by the ageing process. The TEM images showed the influence of ageing during the formation of titanate nanotubes. HRTEM revealed that Pd particle sizes of <1 nm was present inside the tubes.

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Synthesis and Photo-Catalytic Properties Characterization of Graphene/TiO2 Nanotube Composites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.544.21 ◽

2013 ◽

Vol 544 ◽

pp. 21-24

Author(s):

Cai Xia Li ◽

Lin Zhang ◽

Dan Yu Jiang ◽

Qiang Li

Keyword(s):

Catalytic Properties ◽

Raw Materials ◽

Catalytic Performance ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Nanotube Composites ◽

Degussa P25 ◽

Concentrated Solution

Selecting graphene oxide (GO) and the Degussa P25 TiO2 (80% anatase and 20% rutile) as raw materials, the composites of graphene/TiO2 nano-tubes were simply and quickly prepared under the conditions of a concentrated solution of sodium hydroxide. The as-obtained composites’ phase structure was analyzed and characterized by powder X-ray diffraction (XRD), their morphologies were also observed and cross-confirmed under the Transmission Electron Microscopy (TEM). The measurements showed that the composites prepared in this work have a remarkable structure, and compared to the seperate TiO2 nano-tubes, the agglomeration of TiO2 nano-tubes covered on the surface of the graphene is apparently not so serious. In view of this, we preliminary tested the composites’ photo-catalytic performance with the visible light irradiation, and also made a comparison with TiO2 nano-tubes.

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Analysis of transition alumina structures using HRTEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100113123 ◽

1984 ◽

Vol 42 ◽

pp. 648-649

Author(s):

K. J. Morrissey ◽

K. K. Czanderna ◽

R. P. Merrill ◽

C. B. Carter

Keyword(s):

High Surface ◽

High Surface Area ◽

Acid Sites ◽

X Ray Diffraction ◽

Transition Alumina ◽

X Ray ◽

Co Catalysts ◽

Transmission Electron ◽

Special Surface ◽

Materials Used

The transition aluminas are important materials used as catalysts, co-catalysts, catalyst supports, and adsorbents, γ-alumina is used in catalysis because it has a high surface area and an inherent defect structure. Much of the special surface chemistry is attributed to defect acid sites. These sites apparently occur during the dehydroxyilation of the oxyhydroxides which are their precursors. The structure of γ-Al2O3 is not well understood; most of the previous structure analysis has used powder x-ray diffraction. In this study high resolution transmission electron microscopy (HRTEM) and selected area diffraction (SAD) were used to investigate the structure and the defect nature of the aluminas.

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Ferromagnetic Property and Synthesis of Onion-Like Fullerenes by Chemical Vapor Deposition Using Fe and Co Catalysts Supported on NaCl

Journal of Nanomaterials ◽

10.1155/2011/720937 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6

Author(s):

Yongzhen Yang ◽

Xuguang Liu ◽

Yanxing Han ◽

Wenfang Ren ◽

Bingshe Xu

Keyword(s):

Electron Microscopy ◽

Vapor Deposition ◽

Chemical Vapor ◽

X Ray Diffraction ◽

Ferromagnetic Property ◽

X Ray ◽

Co Catalysts ◽

Transmission Electron ◽

Morphology And Structure ◽

Co Nanoparticles

Metal-encapsulating onion-like fullerenes (M@OLFs) were synthesized by CVD at relatively low temperature (420C∘) using Fe and Co nanoparticles impregnated into NaCl as catalyst. The morphology and structure of the products were characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The results show that Fe@OLFs and Co@OLFs with stacked graphitic fragments were prepared using Fe/NaCl or Co/NaCl as catalysts; after Co@OLFs were immersed in concentrated HCl for 48 hours, Co nanoparticles encapsulated by carbon shells were not removed, meaning that carbon shells can protect the encapsulated Co cores against environmental degradation. The coercivity value (750.23 Oe) of Co@OLFs showed an obvious magnetic property.

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Titanate Nanotubes as Futuristic Catalyst Support Material

10.35940/ijitee.k9488.10101221 ◽

2021 ◽

Vol 10 (12) ◽

pp. 24-27

Author(s):

Dr. Lucky Sikhwivhilu ◽

◽

Dr. Venkataraman Vishwanathan ◽

Keyword(s):

Surface Composition ◽

Ageing Time ◽

Catalyst Support ◽

Titanate Nanotubes ◽

X Ray Diffraction ◽

Time Intervals ◽

X Ray ◽

Transmission Electron ◽

Base Solution ◽

Degussa P25

Titanate Nanotubes (TNT) were synthesized by aging commercial titanium dioxide (TiO2 - Degussa P25) with an alkali (KOH) solution at different time intervals. The prepared materials were investigated for their surface composition and textural behaviour by X-ray powder diffraction (XRD), Raman spectroscopy, Gas (N2 and CO2) adsorption measurements, and Transmission electron microscopy (TEM). The X-ray diffraction spectra revealed the decrease in the crystalline nature of the materials decreased by exposing them for a longer duration in the base solution. Raman spectra results showed that ageing time affected the structural properties. The specific surface area and the pore size of the newly synthesised materials were affected by the ageing process. The TEM images showed the influence of ageing during the formation of titanate nanotubes. HRTEM revealed that Pd particle sizes of <1 nm was present inside the tubes.

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The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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