scholarly journals The Enhancement of Visible Absorption of Cu Doped ZnO Nanorods on Patterned Substrates

Author(s):  
My Hoa Tong ◽  
Thi Hoa Lai ◽  
Nhat Minh Nguyen ◽  
Thi Kieu Hanh Ta ◽  
Thanh Tuan Anh Pham ◽  
...  

: We report the antireflection and light absorption in visible region by new stretchable substrates with patterned structure. Mogul substrates with 3-Dimentional structures were fabricated by using polydimethyl – siloxane that imitate the nanostructures surface. Then, Copper doped ZnO NRs on mogul-patterned surface by hydrothermal method at low temperature. The optical properties, morphology and structures of ZnO:Cu NRs were investigated through out of measurement the scanning electron microscopy, X-Ray diffraction and ultraviolet-visible spectroscopy, respectively. The results show the Cu doped ZnO NRs were uniformly and dense grown on mogul substrates, well oriented in the (002) plane. Additionally, the light absorption can be significantly enhanced to more 10% in a wide spectral range (400-800 nm) due to the reduce reflection. Growing ZnO NRs doping on new stretchable substrates with a mogul-patterned surface were successfully fabricated and applicable in the flexible and stretchable optoelectronic devices.  

2016 ◽  
Vol 09 (03) ◽  
pp. 1650039 ◽  
Author(s):  
Jingyuan Piao ◽  
Li-Ting Tseng ◽  
Kiyonori Suzuki ◽  
Jiabao Yi

Na-doped ZnO nanorods have been fabricated through a hydrothermal method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses indicate that the d spacing of ZnO increases with increasing doping concentration, suggesting the effective incorporation of dopant Na in the samples. Electron paramagnetic resonance (EPR) measurements indicate that there are shallow donors in pure ZnO samples and the shallow donors are strongly prohibited by Na doping. In addition, the resonance at g = 2.005 suggests the formation of Zn vacancies. Magnetic measurements indicate that pure ZnO is paramagnetic and Na doping leads to ferromagnetism at room temperature. Moreover, 0.5% Na-doped ZnO nanorods exhibits the largest saturation magnetization.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Honghui Teng ◽  
Shukun Xu ◽  
Dandan Sun ◽  
Ying Zhang

Fe-doped TiO2nanotubes (Fe-TNTs) have been prepared by ultrasonic-assisted hydrothermal method. The structure and composition of the as-prepared TiO2nanotubes were characterized by transmission electron microscopy, X-ray diffraction, and UV-Visible absorption spectroscopy. Their photocatalytic activities were evaluated by the degradation of MO under visible light. The UV-visible absorption spectra of the Fe-TNT showed a red shift and an enhancement of the absorption in the visible region compared to the pure TNT. The Fe-TNTs were provided with good photocatalytic activities and photostability and under visible light irradiation, and the optimum molar ratio of Ti : Fe was found to be 100 : 1 in our experiments.


2013 ◽  
Vol 291-294 ◽  
pp. 2731-2733
Author(s):  
Shu Ming Yang ◽  
Guang Hui Zhu ◽  
Shu Pei Guo

In this paper, Al(NO3)3•9H2O was used as raw material and the nanoparticles of Al-doped TiO2 were prepared by hydrothermal method. The nanoparticles and films were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Ultraviolet and Visible Spectroscopy (UV-Vis). The flat band potential (Efb) of nanostructured TiO2 and Al-doped TiO2 in acetone have been determined with spectroelectrochemistry measurement. The results show that Al doping decreases the energy gap and improves the absorption ability in visible region. On the other hand, Al doping TiO2 can effectively embarrass the crystal growth of TiO2. Specifically, the Efb of TiO2 and Al-doped TiO2 can be determined to be -0.6 V and -0.3V.


2014 ◽  
Vol 32 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Munirah Munirah ◽  
Ziaul Khan ◽  
Mohd. Khan ◽  
Anver Aziz

AbstractThis paper describes the growth of Cd doped ZnO thin films on a glass substrate via sol-gel spin coating technique. The effect of Cd doping on ZnO thin films was investigated using X-ray diffraction (XRD), UV-Vis spectroscopy, photoluminescence spectroscopy, I–V characteristics and field emission scanning electron microscopy (FESEM). X-ray diffraction patterns showed that the films have preferred orientation along (002) plane with hexagonal wurtzite structure. The average crystallite sizes decreased from 24 nm to 9 nm, upon increasing of Cd doping. The films transmittance was found to be very high (92 to 95 %) in the visible region of solar spectrum. The optical band gap of ZnO and Cd doped ZnO thin films was calculated using the transmittance spectra and was found to be in the range of 3.30 to 2.77 eV. On increasing Cd concentration in ZnO binary system, the absorption edge of the films showed the red shifting. Photoluminescence spectra of the films showed the characteristic band edge emission centred over 377 to 448 nm. Electrical characterization revealed that the films had semiconducting and light sensitive behaviour.


2012 ◽  
Vol 621 ◽  
pp. 172-177 ◽  
Author(s):  
Su Hua Chen ◽  
Bi Xuan Wang ◽  
Xian Hua Qiu ◽  
Zhen Sheng Xiong

In order to improve ZnWO4 photocatalytic activity under visible light, the C, N-codoped ZnWO4 nanoparticles have been successfully synthesized by choosing C3N4 generated from tripolycyanamide pyrolysis as the source of Carbon and Nitrogen and the influence of C3N4 concentration on structural, optical and morphological properties of C, N-codoped ZnWO4 using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM) and photocatalytic decoloration of rhodamine B (RhB) aqueous solution under visible light. It was found that the presence of carbon and nitrogen could not improve the crystallization of ZnWO4 species but could enhance their photoabsorption property in the visible region. The results also showed that the photocatalytic activity of the as-prepared ZnWO4 is higher than that of pure ZnWO4 with the optimum effect occurring at RC3N4 = 9 % (the weight ratio of tripolycyanamide to ZnWO4)


2021 ◽  
Author(s):  
Sayed Abdul Saboor ◽  
Vidhika Sharma ◽  
Ebrima L. Darboe ◽  
Vidya Doiphode ◽  
Ashvini Punde ◽  
...  

Abstract In this paper, Au plasmons and their synergistic effects with ZnO nanorods (ZNs) have been investigated for photoelectrochemical (PEC) water splitting application. Au plasmons and ZNs are deposited electrochemically. Au modified nanostructures have absorption in the visible region as plasmons enhance charge transfer and inhibit charge recombination. ZNs modified with Au (deposition duration ∼ 60 s) has a photo-current density of ∼ 660 µA cm-2, at a bias of 1.0V/SCE. X-ray diffraction and scanning electron microscopy were used to study the structure and surface morphology of fabricated photoanodes. UV-Visible absorption and Photoluminescence spectroscopy were used for optical characterization. We have recorded current-voltage measurements and photo-conversion efficiency measurements to substantiate our observations of the synthesized photoanodes for prospective application in PEC splitting of water. We have also carried out Mott-Schottky, and electrochemical impedance spectroscopy analysis. The analysis reveals that Au modified ZNs based photoanodes are a better proposition than their bare counterparts for PEC water splitting application.


2009 ◽  
Vol 620-622 ◽  
pp. 529-532
Author(s):  
Tie Kun Jia ◽  
Wei Min Wang ◽  
Zheng Yi Fu ◽  
Fei Huang ◽  
Hao Wang

La doped ZnO nanorods were synthesized via solvothermal technique using Zn(AC)2 and La(NO3)3 as starting materials. The products were characterized by X-ray diffraction (XRD), field scanning electron microscopy (FESEM) equipped with an energy dispersion X–ray (EDX) spectrometer, photoluminescence spectroscopy and UV-vis spectroscopy. The results of XRD in combination with EDS indicated that La was successful doped in ZnO. The obtained La doped ZnO sample exhibited nanorod like morphology and the diameter was about 30 nm. The photocatalytic property of La doped ZnO was evaluated by the variation of the concentration of RhB.


2010 ◽  
Vol 148-149 ◽  
pp. 832-836
Author(s):  
Ke Zou ◽  
You Shi Wu ◽  
Jin Bo Zhao ◽  
Li Li Wu

ZnO nanorods doped with Ce4+ ions have been synthesized by a solvothermal method. The concentration level of Ce4+ additive was varied systematically from 1 to 10 mol. %. The structural and optical properties of Ce4+ -doped nanostructures are investigated using X-ray diffraction, transmission electron micrograph, UV-visible absorption and photoluminescence Spectroscopy. The results showed that the concentration increase of Ce4+ doping induce the enhancement of photoluminescence.


2011 ◽  
Vol 688 ◽  
pp. 301-306 ◽  
Author(s):  
Xiao Dan Hu ◽  
Hai Qian Zhang

CdS nanowires were synthesized with tetramethyl thiuram disulfide (TMTD) as a new sulphur source by a solvothermal method in ethylenediamine at 180°C for 24 h. The crystallinity, morphology and probable formation mechanism of CdS nanocrystals were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The optical properties were investigated by ultraviolet-visible spectroscopy (UV-vis) and cathodoluminescence (CL). The results indicated that CdS nanocrystals were hexagonal and had a wire-like morphology with a diameter of 20 to 50 nm. There were blue shifts at the onset of absorption of the CdS nanowire, compared with the absorption of the bulk CdS. The cathodoluminescence (CL) implied that CdS nanowires possessed potential optical property in the visible region.


NANO ◽  
2006 ◽  
Vol 01 (02) ◽  
pp. 153-157 ◽  
Author(s):  
ZHIGANG ZHAO ◽  
FENGXIA GENG ◽  
HONGTAO CONG ◽  
JINBO BAI ◽  
HUI-MING CHENG

Pure and Fe -doped ZnO nanorod bundles were synthesized in aqueous solution at low temperature, in which inexpensive reagents such as Zn ( NO 3)2, NaOH and Fe ( NO 3)3 were used as precursors. The composition of the final product can be roughly tuned by the precursor ratio used. Energy dispersive X-ray spectroscopy confirms the successful incorporation of Fe element into ZnO nanorods, and X-ray diffraction reveals that ZnO nanorod bundles have a pure hexagonal wurtzite-phase structure. UV–vis spectroscopy show that the spectrum shifts to longer wavelength with increasing iron doping.


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