scholarly journals Palygorskite Supported AuPd Alloy Nanoparticles as Efficient Nano-Catalysts for the Reduction of Nitroarenes and Dyes at Room Temperature

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1000 ◽  
Author(s):  
Jun Xu ◽  
Shengli Guo ◽  
Lei Jia ◽  
Wensheng Zhang
Keyword(s):  
Room Temperature ◽  
Catalytic Performance ◽  
Atomic Ratio ◽  
Alloy Nanoparticles ◽  
X Ray ◽  
Degradation Of Dyes ◽  
Transmission Electron ◽  
Catalytic Stability ◽  
Nano Catalysts ◽  
Co Reduction

In this work, AuPd alloy palygorskite based Pal-NH2@AuPd nano-catalysts were prepared and used as catalysts for the reduction of nitroarenes and dyes at room temperature. The surface of palygorskite (Pal) was first modified with 3-aminpropyltriethoxysilane, and then covered with AuPd alloy nanoparticles through co-reduction of HAuCl4 and K2PdCl4. The morphology and structures of the Pal-NH2@AuPd nano-catalysts were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). The as-synthesized Pal-NH2@AuPd nano-catalysts displayed excellent catalytic performance in reducing 4-nitrophenol (4-NP) and various other nitroaromatic compounds. Moreover, the catalytic activities of the Pal-NH2@AuPd nano-catalysts were adjustable via changing the atomic ratio of AuPd alloy nanoparticles, leading to the Pal-NH2@Au48Pd52 component as having the best atomic ratio. The Pal-NH2@Au48Pd52 continued to display good catalytic stability after being reused for several cycles and there were no obvious changes, either of the morphology or the particle size distribution of the nano-catalysts. Furthermore, these Pal-NH2@Au48Pd52 nano-catalysts also provided a convenient and accessible way for the degradation of dyes in artificial industrial wastewater.

A Chemical Solution Route to Rapid Synthesis of Homogeneous Bi100−xSbx Alloys Nanoparticles at Room Temperature

2007 ◽  
Vol 7 (2) ◽  
pp. 525-529 ◽  
Author(s):  
Bo Zhou ◽  
Jun-Jie Zhu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Solution Route ◽  
Diffraction Patterns ◽  
Co Reduction ◽  
Chemical Solution Route

A chemical co-reduction route in aqueous solution was developed to synthesize Bi100−xSbx alloys at room temperature. The hydrolyses of Bi(III) and Sb(III) were effectively avoided by selecting proper raw materials and coordinator. X-ray diffraction analysis indicated that the as-prepared Bi100−xSbx alloys were homogeneous and phase-pure, and the Bi/Sb ratios in the alloys were very close to those in the aqueous solutions. The transmission electron microscope observation showed that the as-prepared Bi100−xSbx (x = 0∼100) alloys were particles with a size of tens of nanometers. The selected area electron diffraction patterns confirmed the high crystallinity, the homogeneousness, and the composition controllability of as-prepared alloys. All these characters and the nanometer-scaled size of the alloys are believed to be beneficial to the thermoelectric property of the Bi100−xSbx alloys.

scholarly journals Magnetic Au-Ag-γ-Fe2O3/rGO Nanocomposites as an Efficient Catalyst for the Reduction of 4-Nitrophenol

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 877 ◽  
Author(s):  
Guangyu Lei ◽  
Jingwen Ma ◽  
Zhen Li ◽  
Xiaobin Fan ◽  
Wenchao Peng ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
X Ray Diffraction ◽  
Efficient Catalyst ◽  
Reaction Systems ◽  
X Ray ◽  
Transmission Electron ◽  
The Impact

In this paper, a facile route has been developed to prepare magnetic trimetallic Au-Ag-γ-Fe2O3/rGO nanocomposites. The impact of the preparation method (the intensity of reductant) on the catalytic performance was investigated. The nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The prepared nanocomposites show fine catalytic activity towards the reduction reaction of 4-nitrophenol (4-NP). The nanocomposites also have superparamagnetism at room temperature, which can be easily separated from the reaction systems by applying an external magnetic field.

Removal of Formaldehyde Using Mn-Ce-Fe Oxide Catalyst

2013 ◽  
Vol 634-638 ◽  
pp. 567-570
Author(s):  
Hai Zhao ◽  
Ke Jian Han ◽  
Yao Tong ◽  
Xiao Qi Sha ◽  
Yang Yang Li
Keyword(s):  
Room Temperature ◽  
Oxide Catalyst ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Fe Oxide ◽  
X Ray ◽  
Surface Areas ◽  
Transmission Electron ◽  
Co Precipitation

Mn-Ce-Fe Oxide catalysts were prepared by a co-precipitation method using precipitants NH4OH. The catalysts were characterized by Powder X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and BET study. It was found that the samples prepared with NH4OH as a precipitator show higher surface areas and sSubscript textuperior catalytic performance at room temperature. The catalysts would reduce substantially indoor formaldehyde concentrations in the present of airstreams.

Preparation of Carbon-Encapsulated Alloy Nanomaterials by Detonation Decomposition of Nitrate Complex Explosives Containing Multi-Metallic Ions

2011 ◽  
Vol 335-336 ◽  
pp. 249-254 ◽  
Author(s):  
Xiao Jie Li ◽  
Ning Luo ◽  
Kai Xin Liu
Keyword(s):  
Room Temperature ◽  
Magnetic Measurements ◽  
Composite Particles ◽  
Alloy Nanoparticles ◽  
Metallic Ions ◽  
Nitrate Complex ◽  
X Ray ◽  
Transmission Electron ◽  
Prepared Composite ◽  
Iron Based

Carbon-encapsulated iron-based alloy nanoparticles with a core-shell structure were prepared by detonation decomposition of nitrate complex explosives containing multi-metallic ions. The size and magnetic properties of the as-prepared composite particles were revealed by X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray detector and magnetic measurements. Results showed that the different sizes of the ferronickel and ferrocobalt nanocrystal core and the thickness of the carbon shell could be yielded by adjusting the component materials of the explosives. The composite particles had a gamma- or alpha- ferronickel or bcc-ferrocobalt nanocrystal core with a coating of graphitic carbon layers. Magnetic measurements indicated these composite nanoparticles were superparamagnetism at the room temperature, with some variation in the values of saturation magnetization, remanences and coercive forces.

Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hexagonal Structure ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Morphological Studies ◽  
Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

scholarly journals Facile Organometallic Synthesis of Fe-Based Nanomaterials by Hot Injection Reaction

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1141
Author(s):  
Georgia Basina ◽  
Hafsa Khurshid ◽  
Nikolaos Tzitzios ◽  
George Hadjipanayis ◽  
Vasileios Tzitzios
Keyword(s):  
Room Temperature ◽  
Colloidal Particles ◽  
Iron Pentacarbonyl ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Organometallic Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Hot Injection ◽  
The Stability

Fe-based colloids with a core/shell structure consisting of metallic iron and iron oxide were synthesized by a facile hot injection reaction of iron pentacarbonyl in a multi-surfactant mixture. The size of the colloidal particles was affected by the reaction temperature and the results demonstrated that their stability against complete oxidation related to their size. The crystal structure and the morphology were identified by powder X-ray diffraction and transmission electron microscopy, while the magnetic properties were studied at room temperature with a vibrating sample magnetometer. The injection temperature plays a very crucial role and higher temperatures enhance the stability and the resistance against oxidation. For the case of injection at 315 °C, the nanoparticles had around a 10 nm mean diameter and revealed 132 emu/g. Remarkably, a stable dispersion was created due to the colloids’ surface functionalization in a nonpolar solvent.

scholarly journals Enhanced Photocatalytic Activity of Cu2O Cabbage/RGO Nanocomposites under Visible Light Irradiation

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1712
Author(s):  
Appusamy Muthukrishnaraj ◽  
Salma Ahmed Al-Zahrani ◽  
Ahmed Al Otaibi ◽  
Semmedu Selvaraj Kalaivani ◽  
Ayyar Manikandan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermo Gravimetric Analysis ◽  
Visible Region ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dye Pollutants ◽  
Transmission Electron

Towards the utilization of Cu2O nanomaterial for the degradation of industrial dye pollutants such as methylene blue and methyl orange, the graphene-incorporated Cu2O nanocomposites (GCC) were developed via a precipitation method. Using Hummers method, the grapheme oxide (GO) was initially synthesized. The varying weight percentages (1–4 wt %) of GO was incorporated along with the precipitation of Cu2O catalyst. Various characterization techniques such as Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), UV–visible diffused reflectance (UV-DRS), Raman spectroscopy, thermo gravimetric analysis (TGA), energy-dispersive X-ray analysis (EDX), and electro chemical impedance (EIS) were followed for characterization. The cabbage-like morphology of the developed Cu2O and its composites were ascertained from field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HR-TEM). In addition, the growth mechanism was also proposed. The results infer that 2 wt % GO-incorporated Cu2O composites shows the highest value of degradation efficiency (97.9% and 96.1%) for MB and MO at 160 and 220 min, respectively. Further, its catalytic performance over visible region (red shift) was also enhanced to an appreciable extent, when compared with that of other samples.

ION CHANNELING AND PIXE STUDIES OF S IMPLANTATION IN GaAs

1992 ◽  
Vol 02 (02) ◽  
pp. 151-159
Author(s):  
LIU SHIJIE ◽  
WANG JIANG ◽  
HU ZAOHUEI ◽  
XIA ZHONGHUONG ◽  
GAO ZHIGIANG ◽  
...  
Keyword(s):  
Room Temperature ◽  
Dislocation Loops ◽  
Good Recovery ◽  
Electrical Measurements ◽  
X Ray ◽  
Defect Complexes ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Activation Efficiency ◽  
Very High

GaAs (100) crystals were implanted with 100 keV S+ to a dose of 3×1015 cm−2 in a nonchanneling direction at room temperature, and treated with rapid thermal annealing (RTA). He+ Rutherford backscattering and particle-induced X-ray emission in channeling mode in combination with transmission electron microscopy (TEM) were used to study the damage and the lattice location of S atoms. It is revealed that the RTA at 950 °C for 10 sec has resulted in a very good recovery of crystallinity with a few residual defects in the form of dislocation loops, and a very high substitutionality (~90%). The activation efficiency and the Hall mobility of the implanted samples are found to be low after the electrical measurements. Based on these results an extended dopant diffusion effect for the residual defects and a correlation between the electrical properties and defect complexes are suggested.

Synthesis and Photoluminescence Properties of Novel SnO2 Zigzag Nanoribbons

2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Ceramic Boat

Novel single-crystalline SnO2 zigzag nanoribbons have been successfully synthesized by chemical vapour deposition. Sn powder in a ceramic boat covered with Si plates was heated at 1100°C in a flowing argon atmosphere to get deposits on a Si wafers. The main part of deposits is SnO2 zigzag nanoribbons. They were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM observations reveal that the SnO2 zigzag nanoribbons are almost uniform, with lengths near to several hundred micrometers and have a good periodically tuned microstructure as the same zigzag angle and growth directions. Possible growth mechanism of these zigzag nanoribbons was discussed. A room temperature PL spectrum of the zigzag nanoribbons shows three peaks at 373nm, 421nm and 477nm.The novel zigzag microstructures will provide a new candidate for potential application.

Evaluation Humidity Sensing Properties of Graphene/HS-TiO2 Nanocomposites

2021 ◽  
Vol 21 (10) ◽  
pp. 5143-5149
Author(s):  
Zhen Zhu ◽  
Wang-De Lin
Keyword(s):  
Room Temperature ◽  
Response Times ◽  
Sol Gel ◽  
Hollow Spheres ◽  
High Sensitivity ◽  
Humidity Sensing ◽  
X Ray ◽  
Transmission Electron ◽  
Recovery Times ◽  
Relative Humidity Range

This paper reports on a nanocomposite synthesized by sol–gel procedure comprising graphene sheets with hollow spheres of titanium dioxide (G/HS-TiO2) with varying weight percentages of graphene for the purpose of humidity sensors. The surface morphology of the nanocomposite was characterized using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The structural properties were examined using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The response to 12–80% RH at room temperature exhibited sensitivity (S = 135). However, the relative humidity range of 12–90% at room temperature exhibited higher sensitivity (S = 557). Sensors fabricated using the proposed nanocomposite exhibited high sensitivity to humidity, high stability, rapid response times, and rapid recovery times with hysteresis error of less than 1.79%. These results demonstrate the outstanding potential of his material for the monitoring of atmospheric humidity. This study also sought to elucidate the mechanisms underlying humidity sensing performance.

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