scholarly journals Fabrication and Characteristics of MacroporousTiO2Photocatalyst

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Guiyun Yi ◽  
Baolin Xing ◽  
Jianbo Jia ◽  
Liwei Zhao ◽  
Yuanfeng Wu ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Anatase Phase ◽  
High Specific Surface Area ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Energy Conversion And Storage ◽  
And Storage ◽  
Differential Thermogravimetry

Macroporous TiO2photocatalyst was synthesized by a facile nanocasting method using polystyrene (PS) spherical particles as the hard template. The synthesized photocatalyst was characterized by transmission electron microscope (TEM), scanning electron microscopy (SEM), thermogravimetry-differential thermogravimetry (TG-DTG), X-ray diffraction (XRD), and N2-sorption. TEM, SEM, and XRD characterizations confirmed that the macroporous TiO2photocatalyst is composed of anatase phase. The high specific surface area of 87.85 m2/g can be achieved according to the N2-sorption analysis. Rhodamine B (RhB) was chosen as probe molecule to evaluate the photocatalytic activity of the TiO2catalysts. Compared with the TiO2materials synthesized in the absence of PS spherical template, the macroporous TiO2photocatalyst sintered at 500°C exhibits much higher activity on the degradation of RhB under the UV irradiation, which can be assigned to the well-structured macroporosity. The macroporous TiO2material presents great potential in the fields of environmental remediation and energy conversion and storage.

Enhanced photodegradation activity of electrospun porous TiO2 fibers

2019 ◽  
Vol 12 (06) ◽  
pp. 1941002 ◽  
Author(s):  
Peng Zhao ◽  
Peipei Huo ◽  
Xinxu Han ◽  
Bo Liu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Anatase Phase ◽  
Mesoporous Structure ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
Hollow Nanofibers ◽  
X Ray ◽  
Transmission Electron ◽  
Calcination Method

Mesoporous titanium dioxide (TiO2) hollow nanofibers (HNFs) were successfully prepared by a facile electrospinning and calcination method. Techniques such as X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to characterize TiO2 fibers. It was revealed that TiO2 crystals with an appropriate anatase fraction (71.58%) were grown and a tubular mesoporous structure was formed with a high specific surface area. Photodecomposition of methyl orange (MO) solution showed that TiO2 HNFs exhibited much higher photocatalytic activity than corresponding TiO2 nanofibers (NFs) and loose-structured nanofibers (LNFs). The significant enhancement of photocatalytic activity was attributed to both the sufficient growth of active anatase phase primarily and a tubular mesoporous nature of TiO2 HNFs.

Preparation of nanocrystalline titania powder via aerosol pyrolysis of titanium tetrabutoxide

1999 ◽  
Vol 14 (10) ◽  
pp. 3938-3948 ◽  
Author(s):  
P. P. Ahonen ◽  
E. I. Kauppinen ◽  
J. C. Joubert ◽  
J. L. Deschanvres ◽  
G. Van Tendeloo
Keyword(s):  
Electron Microscopy ◽  
Ultrafine Particles ◽  
Anatase Phase ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Raman And Infrared Spectroscopy ◽  
Nanocrystalline Titanium ◽  
Titanium Tetrabutoxide

Nanocrystalline titanium dioxide was prepared via aerosol pyrolysis of titanium alkoxide precursor at 200–580 °C in air and in nitrogen atmospheres. Powders were characterized by x-ray diffraction, thermogravimetric analysis, Brunauer–Emmett–Teller analysis, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, x-ray fluorescence, Raman and infrared spectroscopy, and Berner-type low-pressure impactor. The anatase phase transition was initiated at 500 °C in nitrogen and at 580 °C in air. Under other conditions amorphous powders were observed and transformed to nanocrystalline TiO2 via thermal postannealing. In air, smooth and spherical particles with 2–4-μm diameter were formed with an as-expected tendency to convert to rutile in the thermal postannealings. In nitrogen, a fraction of the titanium tetrabutoxide precursor evaporated and formed ultrafine particles via the gas-to-particle conversion. At 500 °C thermally stable anatase phase was formed in nitrogen. A specific surface area as high as 280 m2 g−1 was observed for an as-prepared powder.

Ag2O/ZnO Heterostructures with Enhanced Photocatalytic Activity

2021 ◽  
Vol 1035 ◽  
pp. 1043-1049
Author(s):  
Di Xiang ◽  
Chang Long Shao
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Environmental Remediation ◽  
Organic Dyes ◽  
Light Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
P Type

A simple route has been developed for the synthesis of Ag2O/ZnO heterostructures and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) spectroscopy analysis. Considering the porous structure of Ag2O/ZnO, the photocatalytic degradation for the organic dyes, such as eosin red (ER), methyl orange (MO), methylene blue (MB) and rhodamine B (RhB), under visible light irradiation was investigated in detail. Noticeably, Ag2O/ZnO just took 40 min to degrade 96 % MB. The rate of degradation using the Ag2O/ZnO heterostructures was 2.3 times faster than that of the bare porous ZnO nanospheres under visible light irradiation due to that the recombination of the photogenerated charge was inhibited greatly in the p-type Ag2O and n-type ZnO semiconductor. So the Ag2O/ZnO heterostuctures showed the potential application on environmental remediation.

scholarly journals Biomass-Derived Activated Carbon as a Catalyst for the Effective Degradation of Rhodamine B dye

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 926
Author(s):  
Shamim Ahmed Hira ◽  
Mohammad Yusuf ◽  
Dicky Annas ◽  
Hu Shi Hui ◽  
Kang Hyun Park
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
High Specific Surface Area ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Transmission Electron

Activated carbon (AC) was fabricated from carrot waste using ZnCl2 as the activating agent and calcined at 700 °C for 2 h in a tube furnace. The as-synthesized AC was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis; the results revealed that it exhibited a high specific surface area and high porosity. Moreover, this material displayed superior catalytic activity for the degradation of toxic Rhodamine B (RhB) dye. Rate constant for the degradation of RhB was ascertained at different experimental conditions. Lastly, we used the Arrhenius equation and determined that the activation energy for the decomposition of RhB using AC was approximately 35.9 kJ mol−1, which was very low. Hopefully it will create a great platform for the degradation of other toxic dye in near future.

Nickel Ferrite: Combustion Synthesis, Characterization and Magnetic Properties

2005 ◽  
Vol 498-499 ◽  
pp. 618-623 ◽  
Author(s):  
Ana Cristina Figueiredo de Melo Costa ◽  
Lucianna Gama ◽  
M.R. Morelli ◽  
Ruth Herta Goldsmith Aliaga Kiminami
Keyword(s):  
Magnetic Properties ◽  
Nickel Ferrite ◽  
High Speed ◽  
High Specific Surface Area ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Railway Systems ◽  
Transmission Electron ◽  
Dry Pressing

Nanosized spinel nickel ferrite particles have attracted considerable attention and efforts continue to investigate them for their technological importance to the microwave industries, high speed digital tap or disk recording, repulsive suspension for use in levitated railway systems, ferrofluids, catalysis and magnetic refrigeration systems. Nanosize nickel ferrite powders (NiFe2O4) have been prepared by combustion reaction using nitrates and urea as fuel. The resulting powders were characterized by X-ray diffraction (XRD), BET, and transmission electron microscopy (TEM). The results showed nanosize nickel ferrite powders with high specific surface area (55.21 m2/g). The powders showed extensive XRD line broadening and the crystallite size calculated from the XRD line broadening was 18.0 nm. The samples were uniaxially compacted by dry pressing, sintered at 1200°C/2h and characterized by bulk density, SEM and magnetic properties measurements. The samples showed uniform microstructures with grain size of 4.45 μm, maximum flux density of 0.18T, field coercive of the 488 A/m, and hysteresis loss of 47.58 W/kg.

Laccase Biosensor Based on Ag-Doped TiO2 Nanoparticles on CuCNFs for the Determination of Hydroquinone

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650132 ◽  
Author(s):  
Jie Yang ◽  
Dawei Li ◽  
Zengyuan Pang ◽  
Qufu Wei
Keyword(s):  
Electron Microscopy ◽  
Storage Stability ◽  
Electrochemical Impedance ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
New Material ◽  
And Storage

A novel nanomaterial composed of copper and carbon nanofibers (CuCNFs) decorated with Ag-doped TiO2 (Ag–TiO[Formula: see text] nanoparticles was prepared through electrospinning, carbonization and solvothermal treatment. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The obtained composites were mixed with laccase and Nafion to construct novel hydroquinone biosensor. The electrochemical behavior of the novel biosensor was studied using cyclic voltammetry (CV) and chronoamperometry. The results demonstrated that the biosensor possessed a wide detection linear range (1.20–176.50[Formula: see text][Formula: see text]M), a good selectivity, repeatability, reproducibility and storage stability. This work provides a new material to design more efficient laccase (Lac) based biosensor for hydroquinone detection.

NdFe2O4 Nanoparticles: Synthesis, Characterization, and Magnetic Properties

2020 ◽  
Vol 12 (6) ◽  
pp. 810-814 ◽  
Author(s):  
Xiao-Lei Song ◽  
Yi-Lin Wu ◽  
Si-Ran Zhang ◽  
Zhi Chen ◽  
Yong-Gui Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solvothermal Method ◽  
Energy Dispersive Spectrometer ◽  
Reaction Times ◽  
Spherical Particles ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Parameters ◽  
Transmission Electron

Multi-structured NdFe2O4 magnetic nanoparticles (NPs) were successfully prepared at different reaction times through a convenient solvothermal method. The microstructure and elemental composition of the NPs were characterized using powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) technique. An energy dispersive spectrometer (EDS) was connected to a scanning electron microscope to determine the weight and atomic percent of the prepared products. Subsequently, high-resolution transmission electron microscopy (HR/TEM) and TEM were performed at 3, 7, 11, and 15 h to elucidate the synthetic mechanism of the rare-earth element Nd doped in Fe3O4. The magnetic activities of the NPs were evaluated using a vibrating sample magnetometer (VSM). XRD, EDS, and XPS analyses show that Nd was successfully doped into Fe3O4 without breaking its crystal structure. Procedural single-crystal nanosheets and final spherical particles of NdFe2O4 were verified by TEM. The magnetic parameters of the products were further analyzed using the VSM.

Three-dimensional morphology of anatase nanocrystals obtained from supercritical flow synthesis with industrial grade TiOSO4 precursor

2019 ◽  
Vol 75 (6) ◽  
pp. 1086-1095 ◽  
Author(s):  
Jinlong Yu ◽  
Frederik Søndergaard-Pedersen ◽  
Aref Mamakhel ◽  
Paolo Lamagni ◽  
Bo Brummerstedt Iversen
Keyword(s):  
Three Dimensional ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
Titanyl Sulfate ◽  
Supercritical Flow ◽  
Price Expectation ◽  
X Ray ◽  
Industrial Grade ◽  
Transmission Electron ◽  
Dimensional Reconstruction

Anatase TiO2 (a-TiO2) nanocrystals are vital in catalytic applications both as catalysts (e.g. photodegradation) and as a carrier material (e.g. NOx removal from exhaust). The synthesis of a-TiO2 nanocrystals and their properties have been heavily scrutinized, but there exists a clear gap between the scientific literature, and the scale and price expectation of industrial application. Here it is demonstrated that the industrially most attractive Ti precursor, titanyl sulfate (TiOSO4), can be combined with the green, scalable and fast supercritical flow method to produce phase pure and highly crystalline a-TiO2 nanoparticles with high specific surface area. Control of the nanocrystal morphology is important since it is known that certain facets substantially promote catalytic activity. It is, however, in itself challenging to determine nanocrystal morphology to provide a rational basis for the synthesis control. Here we advocate the use of advanced Rietveld refinement of powder X-ray diffraction data including anisotropic size broadening models in aiding to establish the sample three-dimensional morphology. This relatively quick and robust method assists in overcoming the often encountered ambiguity inherent in two-dimensional to three-dimensional reconstruction of selected particle morphologies with transmission electron microscopy and tomography techniques.

scholarly journals Bulky Macroporous TiO2Photocatalyst with Cellular Structure via Facile Wood-Template Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Qingfeng Sun ◽  
Yun Lu ◽  
Jinchun Tu ◽  
Dongjiang Yang ◽  
Jun Cao ◽  
...  
Keyword(s):  
Cellular Structure ◽  
Anatase Phase ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
Photocatalytic Ability ◽  
Xrd Pattern ◽  
X Ray ◽  
Sem Image ◽  
Transmission Electron ◽  
Wood Template

We report a bulky macroporous TiO2particles with cellular structure prepared in the presence of wood slices as template. Firstly, TiO2sol was coated onto the wood slices by repeated dip-coating process. Then, after calcinations at 550°C, the wood template could be removed, and the bulky TiO2structure was obtained. The prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and transmission electron microscope (TEM) techniques. XRD pattern confirmed the crystalline phase of the wood-templated TiO2is anatase phase. And interestingly, from the observation of SEM image, the wood-templated TiO2inherited the initial cellular structures of birch lumber (B. albosinensis Burk), and numerous macropores were observed in the sample. Meanwhile, the wood-templated TiO2presented a superior photocatalytic ability to decompose Rhodamine B (RhB) under ultraviolet irradiation.

scholarly journals Musa acuminata peel extract mediated eco-friendly synthesis of solar light-active ZnO nanosponge for enhanced dyeing wastewater degradation

2020 ◽  
Vol 167 ◽  
pp. 01003
Author(s):  
Jin-Chung Sin ◽  
Ka-Wey Ong ◽  
Sze-Mun Lam ◽  
Honghu Zeng
Keyword(s):  
Environmental Remediation ◽  
Musa Acuminata ◽  
Spherical Particles ◽  
Solar Light ◽  
Textile Dye ◽  
X Ray Diffraction ◽  
X Ray ◽  
Simulated Solar Light ◽  
First Time ◽  
Peel Extract

ZnO nanosponge was synthesized for the first time via a green method using Musa acuminata peel extract. The X-ray diffraction, Raman, energy dispersive X-ray and fourier-transform infrared analyses demonstrated that the synthesized sample was well crystallized and possessed hexagonal wurtzite pure ZnO. The field-emission scanning electron microscopy observation revealed that the ZnO nanosponge was assembled by aggregated spherical particles with sizes of 30-128 nm. Under simulated solar light irradiation, the ZnO nanosponge acted as an excellent photocatalyst for methylene blue and rhodamine B mixtures degradation compared to commercially available TiO2-P25. The enhanced photocatalytic activities of ZnO sample can be attributed to the high generation of hydroxyl radicals as a result of its unique sponge-like porous structure with large surface area. Furthermore, the ZnO nanosponge can be used effectively on the photodegradation of real textile dye wastewater. These characteristics showed that the biosynthesized ZnO nanosponge can be employed as a photocatalyst for environmental remediation.

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