Green preparation of carbon dots for Hg2+ detection and cell imaging

Carbon dots (CDs) also nitrogen-doped CDs (N-CDs) were produced by green hydrothermal synthesis using Pea and ethanediamine as the carbon and nitrogen source, separately. Transmission electron microscopy (TEM) images displayed that the prepared CDs and N-CDs were well dispersed, had a spherical morphology. X-ray diffraction (XRD) figures of CDs and N-CDs presented a graphitic amorphous structure. Fourier transform infrared spectroscopy (FT-IR) verified that CDs and N-CDs carried many different hydrophilic groups (for example hydroxyl, carboxyl/carbonyl, amide, amino groups) on the surface, X-ray photoelectron spectroscopy (XPS) together verified this result. However, the optical properties and fluorescence quantum yield for N-CDs were obviously superior to those of CDs. Furthermore, the prepared N-CDs displayed outstanding advantages including low toxicity, satisfactory biocompatibility, and excellent chemical stability. More prominently, the prepared N-CDs could detect Hg2+ ions with high sensitivity and selectivity in both water samples and HeLa cells.

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HYDROTHERMAL SYNTHESIS OF α-MoO3 NANORODS FOR NO2 DETECTION

International Journal of Nanoscience ◽

10.1142/s0219581x12400443 ◽

2012 ◽

Vol 11 (06) ◽

pp. 1240044 ◽

Cited By ~ 5

Author(s):

SHOULI BAI ◽

SONG CHEN ◽

YUAN TIAN ◽

RUIXIAN LUO ◽

DIANQING LI ◽

...

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Molybdenum Trioxide ◽

Hydrothermal Process ◽

High Sensitivity ◽

X Ray Diffraction ◽

Hydrothermal Temperature ◽

X Ray ◽

Transmission Electron ◽

Ft Ir

Thermodynamically stable molybdenum trioxide nanorods have been successfully synthesized by a simple hydrothermal process. The product exhibits high-quality, single-crystalline layered orthorhombic structure (α- MoO3 ), and aspect ratio over 20 by characterizations of X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and Fourier transform infrared (FT-IR). The growth mechanism of α- MoO3 nanorods can be understood by electroneutral and dehydration reaction, which is highly dependent on solution acidity and hydrothermal temperature. The sensing tests show that the sensor based on MoO3 nanorods exhibits high sensitivity to NO2 and is not interferred by CO and CH4 , which makes this kind sensor a competitive candidate for NO2 detection. The intrinsic sensing performance of MoO3 maybe arise from its nonstoichiometry of MoO3 owing to the presence of Mo5+ and oxygen vacancy in MoO3 lattice, which has been confirmed by X-ray photoelectron spectroscopy (XPS) analysis. The sensing mechanism of MoO3 for NO2 is also discussed.

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Dual Light- and pH-Responsive Composite of Polyazo-Derivative Grafted Cellulose Nanocrystals

Materials ◽

10.3390/ma11091725 ◽

2018 ◽

Vol 11 (9) ◽

pp. 1725 ◽

Cited By ~ 5

Author(s):

Xiaohong Liu ◽

Ming Li ◽

Xuemei Zheng ◽

Elias Retulainen ◽

Shiyu Fu

Keyword(s):

Cellulose Nanocrystals ◽

Photoelectron Spectroscopy ◽

Surface Composition ◽

X Ray Diffraction ◽

Responsive Materials ◽

X Ray ◽

Ph Response ◽

Transmission Electron ◽

Ft Ir ◽

Hexyl Methacrylate

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.

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Preparation, Characterization, and Performance Analysis of S-Doped Bi2MoO6 Nanosheets

Nanomaterials ◽

10.3390/nano9091341 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1341 ◽

Cited By ~ 1

Author(s):

Ruiqi Wang ◽

Duanyang Li ◽

Hailong Wang ◽

Chenglun Liu ◽

Longjun Xu

Keyword(s):

Photoelectron Spectroscopy ◽

Degradation Rate ◽

X Ray Diffraction ◽

Photo Degradation ◽

X Ray ◽

Transmission Electron ◽

Ft Ir ◽

And Performance ◽

Adsorption Desorption ◽

Excellent Stability

S-doped Bi2MoO6 nanosheets were successfully synthesized by a simple hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), elemental mapping spectroscopy, photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS), and UV-visible diffused reflectance spectra (UV-vis DRS). The photo-electrochemical performance of the samples was investigated via an electrochemical workstation. The S-doped Bi2MoO6 nanosheets exhibited enhanced photocatalytic activity under visible light irradiation. The photo-degradation rate of Rhodamine B (RhB) by S-doped Bi2MoO6 (1 wt%) reached 97% after 60 min, which was higher than that of the pure Bi2MoO6 and other S-doped products. The degradation rate of the recovered S-doped Bi2MoO6 (1 wt%) was still nearly 90% in the third cycle, indicating an excellent stability of the catalyst. The radical-capture experiments confirmed that superoxide radicals (·O2−) and holes (h+) were the main active substances in the photocatalytic degradation of RhB by S-doped Bi2MoO6.

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S tudies on the phase transitions and properties of tungsten (VI) oxide nanoparticles by X - Ray diffraction (XRD) and thermal analysis

ASEAN Journal on Science and Technology for Development ◽

10.29037/ajstd.175 ◽

2017 ◽

Vol 26 (1) ◽

Author(s):

S.F. Abdullah ◽

S. Radiman ◽

M.A. Abdul Hamid ◽

N.B. Ibrahim

Keyword(s):

Thermal Analysis ◽

Phase Transitions ◽

Photoelectron Spectroscopy ◽

Average Diameter ◽

Amorphous Structure ◽

X Ray Diffraction ◽

X Ray ◽

Calcination Temperatures ◽

Transmission Electron ◽

Scherrer Formula

Tungsten (VI) oxide, WO3nanoparticles were synthesized by colloidal gas aphrons(CGAs) technique.The resultant WO3nanoparticleswere characterized by thermogravimetric-differential thermal analysis (TG-DTA) and X-Ray diffraction (XRD) measurements in order to determine the phase transitions, the crystallinity and the size of theWO3nanoparticles. As a comparison, transmission electron microscope (TEM) was used to investigate the size of the WO3nanoparticles. The result from XRD and DTA show that the formation of polymorphsWO3nanoparticles have the following sequence: orthorhombic (b-WO3)®monoclinic (g-WO3) ®triclinic (d-WO3) ®monoclinic (e-WO3) with respect to the calcination temperature of 400, 500, 600 and 700°C. No diffraction peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared), suggesting that an amorphous structure was obtained at this temperature whereas the crystallinity had been obtained by the other samples of theWO3nanoparticles at the calcination temperatures of 400, 500, 600 and 700°C. It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ±5), (50 ±5), (150 ±10) and (200 ±10) nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using Debye-Scherrer formula. The TG curve revealed that the WO3nanoparticles is purely anhydrous since the weight loss is insignificant (0.3 –1.4) % from 30 until 600°C for the WO3nanoparticles calcined at 400°C. Finally, the composition and the purity of the WO3nanoparticleshave been examined by X-Ray photoelectron spectroscopy (XPS). Theresults indicate no significant changes to the composition and the purity of the WO3nanoparticle produced due to the temperature variations

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Studies on the phase transitions and properties of tungsten (VI) oxide nanoparticles by X-Ray diffraction (XRD) and thermal analysis

ASEAN Journal on Science and Technology for Development ◽

10.29037/ajstd.300 ◽

2017 ◽

Vol 26 (1) ◽

pp. 13-20 ◽

Cited By ~ 1

Author(s):

S.F. Abdullah ◽

S. Radiman ◽

M.A. Abdul Hamid ◽

N.B, Ibrahim

Keyword(s):

Thermal Analysis ◽

Phase Transitions ◽

Photoelectron Spectroscopy ◽

Average Diameter ◽

Amorphous Structure ◽

X Ray Diffraction ◽

X Ray ◽

Calcination Temperatures ◽

Transmission Electron ◽

Scherrer Formula

Tungsten (VI) oxide, WO3 nanoparticles were synthesized by colloidal gas aphrons (CGAs) technique. The resultant WO3 nanoparticles were characterized by thermogravimetric-differential thermal analysis (TG-DTA) and X-Ray diffraction (XRD) measurements in order to determine the phase transitions, the crystallinity and the size of the WO3 nanoparticles. As a comparison, transmission electron microscope (TEM) was used to investigate the size of the WO3 nanoparticles. The result from XRD and DTA show that the formation of polymorphs WO3 nanoparticles have the following sequence: orthorhombic (bWO3) ® monoclinic (g-WO3) ® triclinic (d-WO3) ® monoclinic (e-WO3) with respect to the calcination temperature of 400, 500, 600 and 700°C. No diffraction peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared), suggesting that an amorphous structure was obtained at this temperature whereas the crystallinity had been obtained by the other samples of the WO3 nanoparticles at the calcination temperatures of 400, 500, 600 and 700°C. It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ± 5), (50 ± 5), (150 ± 10) and (200 ± 10) nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using Debye-Scherrer formula. The TG curve revealed that the WO3 nanoparticles is purely anhydrous since the weight loss is insignificant (0.3 – 1.4) % from 30 until 600°C for the WO3 nanoparticles calcined at 400°C. Finally, the composition and the purity of the WO3 nanoparticles have been examined by X-Ray photoelectron spectroscopy (XPS). The results indicate no significant changes to the composition and the purity of the WO3 nanoparticles produced due to the temperature variations.

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The Construction of the Heterostructural Bi2O3/g-C3N4 Composites with an Enhanced Photocatalytic Activity

NANO ◽

10.1142/s1793292018500637 ◽

2018 ◽

Vol 13 (06) ◽

pp. 1850063 ◽

Cited By ~ 4

Author(s):

Jinhua Zhang ◽

Huiyue Qian ◽

Wencheng Liu ◽

Hao Chen ◽

Yang Qu ◽

...

Keyword(s):

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Photogenerated Electron ◽

X Ray Diffraction ◽

One Pot ◽

X Ray ◽

Air Atmosphere ◽

Transmission Electron ◽

Ft Ir ◽

The One

A heterostructural composite composed of g-C3N4 and Bi2O3 was achieved by the one-pot and thermal-induced polycondensation method using melamine and Bi(NO[Formula: see text] as precursor at 550[Formula: see text]C under air atmosphere. The crystalline phase, components and morphologies of the as-prepared composites were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Besides, the photocatalytic activity of composites was evaluated by degrading RhB aqueous solution at room temperature under visible light irradiation. Compared with bulk g-C3N4, the photocatalytic efficiency of the 0.5% Bi2O3/g-C3N4 (Bi–CN) was increased by up to four times. The introduction of Bi2O3 enhances not only the light absorption ability, but also the separation of photogenerated electron–hole pairs.

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Nanostructure and mechanical properties of WC–SiC thin films

Journal of Materials Research ◽

10.1557/jmr.2002.0457 ◽

2002 ◽

Vol 17 (12) ◽

pp. 3163-3167 ◽

Cited By ~ 14

Author(s):

Jose L. Endrino ◽

James E. Krzanowski

Keyword(s):

Thin Films ◽

Mechanical Properties ◽

Photoelectron Spectroscopy ◽

Nanocrystalline Structure ◽

Amorphous Structure ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Hardness Increase ◽

Carbide Content

The mechanical properties of WC–SiC thin films deposited by dual radio frequency magnetron sputtering were investigated. The films were characterized by x-ray photoelectron spectroscopy, x-ray diffraction (XRD), and transmission electron microscopy (TEM) to evaluate the details of the microstructure and degree of amorphization. The results indicate that small additions of SiC (<25%) can significantly increase hardness compared to a pure WC film, but higher SiC contents do not strongly affect hardness. XRD studies show the SiC had a disordering effect. TEM results showed that WC films had coarse porous structure, but films with a low silicon carbide content (approximately 10 to 25 at%) had a denser nanocrystalline structure. Samples with greater than 25% SiC were amorphous. The initial hardness increase at lower SiC contents correlated well with the observed densification, but the transition to an amorphous structure did not strongly affect hardness.

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Facile Synthesis of Phase Tunable MoO3 Nanostructures and Their Electrochemical Sensing Properties

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17456 ◽

2020 ◽

Vol 20 (5) ◽

pp. 2823-2831

Author(s):

S. Muthamizh ◽

C. Sengottaiyan ◽

R. Jayavel ◽

V. Narayanan

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Electrochemical Sensing ◽

X Ray Diffraction ◽

Facile Synthesis ◽

X Ray ◽

Solid State Decomposition ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Ft Ir

MoO3 nanostructures with tunable phases such as α-MoO3, β-MoO3 and their mixed phases were synthesized via a simple solid state decomposition method and employed as electrocatalyst for the detection of biomolecule. The phase and crystal structure of the synthesized MoO3 nanostructures were confirmed through X-ray diffraction (XRD) studies. The MoO3 nanostructures were also characterized by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and UV-Vis spectroscopy for their structural, chemical state and optical properties, respectively. The observed results confirmed the successful formation of phase tunable MoO3 nanostructures. The surface texture and morphology of the samples was characterized by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The obtained images showed the formation of hexagons, cubes and rods morphology of MoO3. The synthesized MoO3 nanostructures were used to modify the surface of glassy carbon electrode (GCE) to detect biomolecule (quercetin).

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A Facile Synthesis of Graphene-WO3Nanowire Clusters with High Photocatalytic Activity for O2Evolution

International Journal of Photoenergy ◽

10.1155/2014/943537 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6

Author(s):

M.-J. Zhou ◽

N. Zhang ◽

Z. H. Hou

Keyword(s):

Photocatalytic Activity ◽

Water Splitting ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

High Photocatalytic Activity ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Charge Transfer Rate ◽

Ft Ir

In the present work, graphene-WO3nanowire clusters were synthesizedviaa facile hydrothermal method. The obtained graphene-WO3nanowire clusters were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy (DRS) techniques. The photocatalytic oxygen (O2) evolution properties of the as-synthesized samples were investigated by measuring the amount of evolved O2from water splitting. The graphene-WO3nanowire clusters exhibited enhanced performance compared to pure WO3nanowire clusters for O2evolution. The amount of evolved O2from water splitting after 8 h for the graphene-WO3nanowire clusters isca.0.345 mmol/L, which is more than 1.9 times as much as that of the pure WO3nanowire clusters (ca.0.175 mmol/L). The high photocatalytic activity of the graphene-WO3nanowire clusters was attributed to a high charge transfer rate in the presence of graphene.

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Incorporation of Gold Nanoparticles Within Thermoresponsive Microgel Particles: Effect of Crosslinking Density

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.18383 ◽

2008 ◽

Vol 8 (12) ◽

pp. 6283-6289

Author(s):

Yang Dong ◽

Ying Ma ◽

Tianyou Zhai ◽

Yi Zeng ◽

Hongbing Fu ◽

...

Keyword(s):

Gold Nanoparticles ◽

Photoelectron Spectroscopy ◽

Trisodium Citrate ◽

Crosslinking Density ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Microgel Particles ◽

One Step ◽

Ft Ir

Hybrid microgel particles were prepared by one step incubation of poly(N-isopropylacrylamide)-co-poly(acrylic acid) (PNIPAM-co-PAA) and gold nanoparticles (AuNPs). PNIPAM-co-PAA microgel particles were synthesized by surfactant-free emulsion polymerization with different crosslinking densities (4.5 wt.-%, 10 wt.-%, 15 wt.-%, MBA to NIPAM) and AuNPs obtained by trisodium citrate reduction method independently. The effect of crosslinking density of synthesized microgel particles on the loadings of AuNPs was investigated. The results showed that 18±2 nm AuNPs could be well entrapped in the loosely crosslinked (4.5 wt.-%, MBA to NIPAM) PNIPAM-co-PAA microgel particles with high loadings. The final hybrid microgel particles were well characterized by transmission electron microscopy (TEM), UV-vis spectra, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and FT-IR. In particular, the PNIPAM-co-PAA/AuNPs hybrid microgel particles were thermoresponsive and completely reversible with several heating/cooling cycles. Therefore, the PNIPAM-co-PAA/AuNPs hybrid microgel particles allow for combined surface plasmon and thermal switching applications.

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