Preparation and Characterization of ZnS/ZnO Compound Grown on Porous Silicon Substrate Using CVD Method

2010 ◽  
Vol 663-665 ◽  
pp. 393-396
Author(s):  
Fu Ru Zhong ◽  
Xiao Yi Lv ◽  
Zhen Hong Jia

We have investigated the morphology and photoluminescence (PL) of Zinc Oxide (ZnO) and Zinc sulphide (ZnS) compound grown on porous silicon at room temperature. Under different excitation wavelengths (320 nm, 340nm, 370 nm), the photoluminescence (PL) spectra of PS-ZnS-ZnO composites were different, and at 550nm there is a strong photoluminescence peak. Energy dispersive spectroscopy (EDS) has been carried out to evaluate the existing of ZnO/ZnS compound. In addition, the scanning electron microscopy (SEM) observation shows that the morphology of the PS-ZnS-ZnO composites was well grown on porous silicon.

2010 ◽  
Vol 663-665 ◽  
pp. 292-295
Author(s):  
Wen Bin Yang ◽  
Jun Wun ◽  
Fang Fang He ◽  
Xiao Hong Tang ◽  
Yuan Lin Zhou

Porous silicon (PS) of uniform structure was prepared by electroless silver deposition on surface of silicon at near room temperature in HF-AgNO3 system solution. Morphology of PS was characterized by scanning electron microscopy. The results showed that the diameter of hole was 1-2μm and holes distributed regularly. The ethylene diamine tetra acetic acid (EDTA) was an important additive to control the etching rate of silicon, which is of great significance to research the mechanism of porous silicon formation. Furthermore, photoluminescence property of PS was characterized.


2019 ◽  
Vol 824 ◽  
pp. 163-167
Author(s):  
Pema Dechen ◽  
Ekasith Somsook

In this report, synthesis and characterization of gold nanoparticles (AuNPs) from gold leaf by electrolysis in two different media (gel and paper) in presence of sodium chloride (NaCl), glucose (C6H12O6) and polyvinyl pyrrolidone (PVP) at room temperature were investigated. Graphite was used as two electrodes, NaCl was used as an electrolyte, C6H12O6 was used as reducing agent and PVP was used as stabilizer to control the aggregation of the nanoparticles. UV-Visible spectroscopy (UV-Vis) and scanning electron microscopy (SEM) were used to confirm the characteristics and morphologies of the synthesized AuNPs.


NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650079 ◽  
Author(s):  
Wenjun Yan ◽  
Ming Hu ◽  
Jiran Liang ◽  
Dengfeng Wang ◽  
Yulong Wei ◽  
...  

A novel composite of Au-functionalized porous silicon (PS)/V2O5 nanorods (PS/V2O5:Au) was prepared to detect NO2 gas. PS/V2O5 nanorods were synthesized by a heating process of pure vanadium film on PS, and then the obtained PS/V2O5 nanorods were functionalized with dispersed Au nanoparticles. Various analytical techniques, such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), have been employed to investigate the properties of PS/V2O5:Au. Herein, the PS/V2O5:Au sample exhibited improved NO2-sensing performances in response, stability and selectivity at room temperature (25[Formula: see text]C), compared with the pure PS/V2O5 nanorods. These phenomena were closely related to not only the dispersed Au nanoparticles acting as a catalyst but also the p-n heterojunctions between PS and V2O5 nanorods. Whereas, more Au nanoparticles suppressed the improvement of response to NO2 gas.


1996 ◽  
Vol 457 ◽  
Author(s):  
I. Coulthard ◽  
T. K. Sham

ABSTRACTApart from its well known ability to luminesce very intensely at room temperature in the visible range, porous silicon is also an effective reducing agent. We report the formation of several noble metal (Pd, Ag, Au, Pt) nanostructures by reductive dispersion of metal ions from aqueous solutions onto the surface of porous silicon. The nanophase systems produced by reductive deposition vary with the element deposited and the metallic salt utilized in the process. The resulting nanophase systems were studied using a variety of techniques including: scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and spectroscopie methods using synchrotron radiation.


2003 ◽  
Vol 792 ◽  
Author(s):  
V. Shutthanandan ◽  
Y. Zhang ◽  
C. M. Wang ◽  
J. S. Young ◽  
L. Saraf ◽  
...  

ABSTRACTNucleation of gold nanoclusters in TiO2(110) single crystal using ion implantation and subsequent annealing were studied by Rutherford backscattering spectrometry /channeling (RBS/C), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Approximately 1000 Au2+/nm2 were implanted at room temperature in TiO2(110) substrates. TEM and SEM measurements reveal that rounded nanoclusters were formed during the implantation. In contrast, subsequent annealing in air for 10 hours at 1275 K promoted the formation of faceted (rectangular shaped) Au nanostructures in TiO2. RBS channeling measurements further reveled that Au atoms randomly occupied the host TiO2 lattice during the implantation. However, it appears that some Au atoms moved to the Ti lattice positions after annealing.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8191-8201
Author(s):  
Fuqiang Hu ◽  
Yucheng Hu ◽  
Lingling Zhang ◽  
Meixue Gan ◽  
Shangjun Liu ◽  
...  

The aim of this paper was to enhance paper strength in NaOH/thiourea aqueous solution at room temperature. Paper from cotton pulp was saturated with room temperature NaOH/thiourea aqueous solution and placed at a fixed temperature (8, 15, and 20 °C) for a period of time (1 h, 2 h, 4 h, and 6 h). The morphology, X-ray diffraction (XRD), mechanical properties, and density of paper were characterized. The results indicated the paper was self-reinforced. Scanning electron microscopy (SEM) photographs indicated that the structure of the treated papers was increasingly compact with decreasing temperature. The XRD results showed that the crystallinity degree of the paper decreased from 80.0% to 60.0%. The stress at break of the treated papers increased by more than fivefold. The wet tensile strength of the treated papers increased remarkably.


2011 ◽  
Vol 295-297 ◽  
pp. 610-613
Author(s):  
Jiang Feng Gong ◽  
Wei Hua Zhu ◽  
Kai Xiao Zhang ◽  
Ming Yi Liu ◽  
Hai Yan Xie

We report the synthesis and characterization of ZnS nanostructures, which were grown by thermal evaporation of the ZnS powder at high temperature using iron network as the collection substrate. Scanning electron microscopy investigations show that the products present taper-like morphologies. Transmission electron microscopy studies indicate ZnS nanostructures are well crystallized. The formation mechanism of the novel nanostructure is discussed on the basis of the experimental results; The nanostructure is formed due to a fast growth of ZnS nanowire along [0001] and the subsequent “epitaxial” radial growth of the ZnS nanocone along the six (01-10) surfaces around the nanowire. A strong room-temperature photoluminescence in ZnS nanostructures has been demonstrated.


2013 ◽  
Vol 829 ◽  
pp. 366-370 ◽  
Author(s):  
S. Mohammad Reza Mortazavi ◽  
Fereshteh Rashchi ◽  
Rasoul Khayyam Nekouei

In this study, synthesis of tin oxide by anodic oxidation of tin foils at room temperature in oxalic acid has been investigated. The prepared structure was characterized by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). FESEM results showed that the anodization process leads to formation of nanoporous, cuboid and granular structures. EDS analysis in all tested samples showed the constituents of tin and oxygen.


Author(s):  
P. A. Madden ◽  
W. R. Anderson

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.


Author(s):  
A.J. Tousimis ◽  
T.R. Padden

The size, shape and surface morphology of human erythrocytes (RBC) were examined by scanning electron microscopy (SEM), of the fixed material directly and by transmission electron microscopy (TEM) of surface replicas to compare the relative merits of these two observational procedures for this type specimen.A sample of human blood was fixed in glutaraldehyde and washed in distilled water by centrifugation. The washed RBC's were spread on freshly cleaved mica and on aluminum coated microscope slides and then air dried at room temperature. The SEM specimens were rotary coated with 150Å of 60:40- gold:palladium alloy in a vacuum evaporator using a new combination spinning and tilting device. The TEM specimens were preshadowed with platinum and then rotary coated with carbon in the same device. After stripping the RBC-Pt-C composite film, the RBC's were dissolved in 2.5N HNO3 followed by 0.2N NaOH leaving the preshadowed surface replicas showing positive topography.


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