Zinc Oxide/ Silver Sulfide (ZnO/Ag2S) Core-Shell Type Composite for Wide Range Absorption of Visible Spectra: Synthesis and Characterization

2019 ◽  
Vol 25 ◽  
pp. 84-89 ◽  
Author(s):  
Afaf Mohammad Babeer ◽  
Lubna Aamir

This work presents the synthesis of zinc oxide /silver sulfide (ZnO/Ag2S) core/shell type composite; using combined wet chemical precipitation method and ion exchange mechanism; for wide range absorption of visible spectra by the composite. Synthesis is performed in three steps. In the first step; ZnO nanoparticles (nanocores) are produced, in the second step; ZnS layer is deposited over ZnO nanocores and in the third step; Zn from ZnS is replaced by Ag to form Ag2S shell over ZnO; using ion exchange mechanism. The presence of reflection peaks of ZnO and Ag2S in XRD spectra confirms the formation of ZnO/Ag2S composite. SEM image of ZnO shows the formation of near spherical ZnO nanoparticles of diameter in range 256nm to 584nm with a smooth surface, while SEM image of ZnO/Ag2S composite shows the formation of Ag2S layer over ZnO cores as indicated by rougher and contrasted surface as compared to bare ZnO cores. Also, the size of composite particles became larger than ZnO nanocores (100µm-200µm), which further confirms the formation of Ag2S shell over ZnO nanocores. The optical absorption spectrums of both ZnO and ZnO/Ag2S composite clearly indicate that synthesized composite absorb strongly in UV to IR region of the electromagnetic spectrum as compared to ZnO nanocores; which absorb only in UV region. Therefore, the synthesized composite could be used as a photovoltaic material.

2015 ◽  
Vol 3 (8) ◽  
pp. 4239-4247 ◽  
Author(s):  
Tiantian Hong ◽  
Zhifeng Liu ◽  
Hui Liu ◽  
Junqi Liu ◽  
Xueqi Zhang ◽  
...  

A fast, versatile and low-cost hydrothermal chemical synthesis based on ion-exchange has been used to deposit a shell of cupric selenite onto vertically aligned zinc oxide nanorod arrays with a buffer layer of zinc selenite for photoelectrochemical water splitting.


2019 ◽  
Vol 2 (1) ◽  
pp. 42-52
Author(s):  
Abdur Rehman ◽  
Saira Ahmad ◽  
Abdul Mateen ◽  
Huma Qamar ◽  
Mudaber Ahmad Mubashar ◽  
...  

Nanotechnology is the science, engineering and technology conducted at the scale that ranges between 1-100 nanometers. For the bio-application, evolution of nanotechnology is creating the concern of scientists towards the synthesis of nanoparticles. The nanoparticles have unique characteristics as compare to bulk materials. Zinc oxide (ZnO) is a matchless semiconductor and it has been under investigation due to its wide range of applications in various areas like biomedical, electronics, material science and optics. In the present work synthesis of ZnO nanoparticles was carried out by using simple chemical approach, Sol-gel method for being effective and inexpensive, by employing zinc acetate dehydrate Zn (CH3CO2)2.2H2O as a precursor and sodium hydroxide (NaOH) starch as a constant agent. The structural properties of resultant zinc oxide nanoparticles were investigated by X-ray diffraction (XRD) technique. The XRD data confirmed the hexagonal wurtzite structure of ZnO powder confirmed by JCPDS 36-1451 data. Particles size was calculated by Scherrer formula and calculated size was 30.14 nm. These nanoparticles were investigated for inhibition zone of bacterial strain Escherichia coli, a gram-negative microbe, at various concentrations of ZnO nanoparticles. Zinc oxide nanoparticles were very proficient for inhibition of growth of bacterial strain E. coli. The mechanism of ZnO NPs for antibacterial activity is release of reactive oxygen species which not only hydrolyze cell wall but cell membrane and cellular components as well providing a potential bactericidal effect.


2017 ◽  
Vol 44 (10) ◽  
pp. 13-18
Author(s):  
N.S. Serkhacheva ◽  
N.I. Prokopov ◽  
A.Yu. Gerval'd ◽  
N.A. Lobanov ◽  
I.A. Gritskova

Heterophase polymerisation of styrene was carried out, and nanocomposite polystyrene microspheres with a controllable content of ZnO nanoparticles were synthesised. The colloid chemical properties of the obtained polymer suspensions were studied, and it was shown that the particles have a ‘core–shell’ structure with a ZnO content of up to 30%.


Author(s):  
Y. Kokubo ◽  
W. H. Hardy ◽  
J. Dance ◽  
K. Jones

A color coded digital image processing is accomplished by using JEM100CX TEM SCAN and ORTEC’s LSI-11 computer based multi-channel analyzer (EEDS-II-System III) for image analysis and display. Color coding of the recorded image enables enhanced visualization of the image using mathematical techniques such as compression, gray scale expansion, gamma-processing, filtering, etc., without subjecting the sample to further electron beam irradiation once images have been stored in the memory.The powerful combination between a scanning electron microscope and computer is starting to be widely used 1) - 4) for the purpose of image processing and particle analysis. Especially, in scanning electron microscopy it is possible to get all information resulting from the interactions between the electron beam and specimen materials, by using different detectors for signals such as secondary electron, backscattered electrons, elastic scattered electrons, inelastic scattered electrons, un-scattered electrons, X-rays, etc., each of which contains specific information arising from their physical origin, study of a wide range of effects becomes possible.


2021 ◽  
Author(s):  
Yi He ◽  
Lei Xie ◽  
Shixiang Ding ◽  
Yujia Long ◽  
Xinyi Zhou ◽  
...  

Although the zinc oxide (ZnO) with wide distribution is one of the most attractive energy storage materials, the low electronic conductivity and insufficient active sites of bulk ZnO increase the...


Nanoscale ◽  
2021 ◽  
Author(s):  
Keonwon Beom ◽  
Jimin Han ◽  
Hyun-Mi Kim ◽  
Tae-Sik Yoon

Wide range synaptic weight modulation with a tunable drain current was demonstrated in thin-film transistors (TFTs) with a hafnium oxide (HfO2−x) gate insulator and an indium-zinc oxide (IZO) channel layer...


AIP Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 025207
Author(s):  
Jagriti Gupta ◽  
P. A. Hassan ◽  
K. C. Barick

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