scholarly journals Highly Sensitive Magnesium-Doped ZnO Nanorod pH Sensors Based on Electrolyte–Insulator–Semiconductor (EIS) Sensors

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2110
Author(s):  
Ensaf Mohammed Al-Khalqi ◽  
Muhammad Azmi Abdul Hamid ◽  
Naif H. Al-Hardan ◽  
Lim Kar Keng
Keyword(s):  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Magnesium Content ◽  
Hydroxyl Group ◽  
Zno Nanorod ◽  
Ph Sensing ◽  
High Hydrogen ◽  
Surface Hydroxyl ◽  
Highly Sensitive ◽  
The Impact

For highly sensitive pH sensing, an electrolyte insulator semiconductor (EIS) device, based on ZnO nanorod-sensing membrane layers doped with magnesium, was proposed. ZnO nanorod samples prepared via a hydrothermal process with different Mg molar ratios (0–5%) were characterized to explore the impact of magnesium content on the structural and optical characteristics and sensing performance by X-ray diffraction analysis (XRD), atomic force microscopy (AFM), and photoluminescence (PL). The results indicated that the ZnO nanorods doped with 3% Mg had a high hydrogen ion sensitivity (83.77 mV/pH), linearity (96.06%), hysteresis (3 mV), and drift (0.218 mV/h) due to the improved crystalline quality and the surface hydroxyl group role of ZnO. In addition, the detection characteristics varied with the doping concentration and were suitable for developing biomedical detection applications with different detection elements.

Fabrication and characterization of a single-bridge nanorod between microgap electrodes

2014 ◽  
Vol 31 (2) ◽  
pp. 104-107 ◽  
Author(s):  
Qazi Humayun ◽  
Muhammad Kashif ◽  
Uda Hashim
Keyword(s):  
Zinc Acetate Dihydrate ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Zinc Nitrate ◽  
Wet Etching ◽  
Nitrate Hexahydrate ◽  
Zno Nanorod ◽  
Uv Detector ◽  
Etching Technique ◽  
Content Type

Purpose – The purpose of this study was to investigate the performance of a single-bridge ZnO nanorod as a photodetector. Design/methodology/approach – The fabrication of the design sensor with ∼6-μm gap Schottky contacts and bridging of the ZnO nanorod were based on conventional photolithography and wet-etching technique. Prior to bridging, the ZnO nanorods were grown by the hydrothermal process. The 0.35 M seed solution was prepared by dissolving zinc acetate dihydrate in 2-methoxyethanol, and monoethanolamine, which acts as a stabilizer, was added drop-wise. Before starting the solution deposition, and oxide, titanium (Ti) and gold (Au) layer deposition, p-type (100) silicon substrate was cleaned with Radio Corporation of America (RCA1) and RCA2, followed by dipping in diluted hydrofluoric acid. The aged solution was dropped onto the surface of the Au microgap structure, using a spin coater at a spinning speed of 3,000 rpm for 45 seconds, and then dried at 300°C for 15 minutes, followed by annealing at 400°C for 1 hour. The hydrothermal growth was carried out in an aqueous solution of zinc nitrate hexahydrate (0.025 M) and hexamethyltetramine (0.025 M). Findings – In this study, ZnO nanorods were grown on a SiO2 substrate by the hydrothermal method. Microgap electrodes with ∼6-μm spacing were achieved by using the wet-etching process. After the growth process, an area-selective mask was utilized to reduce the number of rods between the nearby gap areas. The obtained single ZnO nanorod was tested for the UV-sensing application. The single ZnO nanorod photodetector exhibited a UV photoresponse, thereby indicating potential as a cost-effective UV detector. The response and recovery times of the fabricated device were 65 and 95 seconds, respectively. Structural analysis was captured using X-ray Diffraction (XRD), whereas surface morphology was determined using scanning electron microscopy. Originality/value – This paper demonstrates the effect of UV photon on a single-bridge ZnO nanorod between microgap electrodes.

scholarly journals The Kinetic Study of The Hydrothermal Growth of Zno Nanorod Array Films / Zno Nanostieņu Kopu Pārklājuma Hidrotermālās Augšanas Kinētikas Izpēte

2015 ◽  
Vol 52 (5) ◽  
pp. 20-27 ◽  
Author(s):  
V. Gerbreders ◽  
P. Sarajevs ◽  
I. Mihailova ◽  
E. Tamanis
Keyword(s):  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Hexagonal Wurtzite Structure ◽  
Hydrothermal Growth ◽  
Solution Temperature ◽  
Zno Films ◽  
Nitrate Hexahydrate ◽  
Zno Nanorod ◽  
Nanorod Arrays ◽  
Kinetics Of

Abstract The simple analysis method has been introduced for the kinetic analysis of the hydrothermal growth. The zinc oxide nanorod arrays have been synthesized via a hydrothermal process. Zinc nitrate hexahydrate (Zn(NO3)2 · 6H2O) has been used as the precursor in the presence of hexamethylenetetramine (C6H12N4) for the formation of ZnO nanostructures. Long-term isothermal growth kinetics of ZnO nanorods has been investigated. The effect of the solution temperature (70-90 ℃) on the kinetics of the hydrothermal growth of ZnO nanorods has been examined. An extensive analysis by scanning electron microscopy, energy dispersive spectroscopy and x-ray diffraction has revealed that the as-synthesized ZnO nanorod arrays are well-crystalline and possessing hexagonal wurtzite structure. These ZnO films have promising potential advantages in microelectronic and optoelectronic applications.

Highly Sensitive Picric Acid Chemical Sensor Based on Samarium (Sm) Doped ZnO Nanorods

2019 ◽  
Vol 19 (6) ◽  
pp. 3637-3642 ◽  
Author(s):  
Yas Al-Hadeethi ◽  
Ahmad Umar ◽  
Kulvinder Singh ◽  
Ahmed A Ibrahim ◽  
Saleh. H Al-Heniti ◽  
...  
Keyword(s):  
Large Scale ◽  
Chemical Sensor ◽  
Limit Of Detection ◽  
Picric Acid ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
High Sensitivity ◽  
Highly Sensitive ◽  
Doped Zno ◽  
Facile Hydrothermal Process

Herein, we report the synthesis, characterization and picric acid chemical sensing application of samarium (Sm) doped ZnO nanorods. The Sm-doped ZnO nanorods were synthesized by facile hydrothermal process and characterized using various analytical methods which confirmed the large-scale synthesis and wurtzite hexagonal crystal structure for the synthesized nanorods. The doping of Sm ions in the lattices of the synthesized nanorods was evaluated by the energy dispersive X-ray spectroscopy (EDS). The synthesized Sm-doped ZnO nanorods were used as potential scaffold to fabricate high sensitive and reproducible picric acid chemical sensor based on I–V technique. The fabricated picric acid chemical sensor based on Sm-doped ZnO nanorods exhibited a high sensitivity of 213.9 mA mM−1 cm−2 with the limit of detection of ∼0.228 mM and correlation coefficient of R═0.9889. The obtained results revealed that the facile grown Sm-doped ZnO nanorods can efficiently be used to fabricate high sensitive and reproducible chemical sensors.

scholarly journals Preparation and Characterization of ZnO/TiO2 Nanocomposite by Anodization and Hydrothermal Synthesis

2015 ◽  
Vol 55 ◽  
pp. 27-33
Author(s):  
Salima Benkara ◽  
Houda Ghamri
Keyword(s):  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Zinc Nitrate ◽  
Zno Nanorod ◽  
Nanorod Arrays ◽  
Zno Nanorod Arrays ◽  
Wurtzite Crystal Structure ◽  
Inorganic Precursors ◽  
Anodization Method

ZnO nanorod arrays were deposited by hydrothermal process via an aqueous solution with ammonia and Zinc nitrate as inorganic precursors, using TiO2 nanotube templates formed in HF solution by anodization method. The effect of NH3.H2O and ZnNO3 concentration on ZnO nanorods morphology and crystallinity were investigated. XRD demonstrates that ZnO nanorods are wurtzite crystal structure preferentially oriented in c-axis direction. The length and the diameter of the ZnO nanorod range from 1,1 mm to 3,4 mm and from 250 to 500 nm respectively.

scholarly journals Graphene Oxide Concentration Effect on the Optoelectronic Properties of ZnO/GO Nanocomposites

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1532
Author(s):  
Issam Boukhoubza ◽  
Mohammed Khenfouch ◽  
Mohamed Achehboune ◽  
Liviu Leontie ◽  
Aurelian Catalin Galca ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Color Space ◽  
Hexagonal Wurtzite Structure ◽  
Zinc Oxide Nanorods ◽  
Luminescence Properties ◽  
A Charge ◽  
Average Coherence ◽  
The Impact

In this work, the effects of graphene oxide (GO) concentrations (1.5 wt.%, 2.5 wt.%, and 5 wt.%) on the structural, morphological, optical, and luminescence properties of zinc oxide nanorods (ZnO NRs)/GO nanocomposites, synthesized by a facile hydrothermal process, were investigated. X-ray diffraction (XRD) patterns of NRs revealed the hexagonal wurtzite structure for all composites with an average coherence length of about 40–60 nm. A scanning electron microscopy (SEM) study confirmed the presence of transparent and wrinkled, dense GO nanosheets among flower-like ZnO nanorods, depending on the GO amounts used in preparation. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis) absorption spectroscopy, and photoluminescence (PL) measurements revealed the impact of GO concentration on the optical and luminescence properties of ZnO NRs/GO nanocomposites. The energy band gap of the ZnO nanorods was independent of GO concentration. Photoluminescence spectra of nanocomposites showed a significant decrease in the intensities in the visible light range and red shifted suggesting a charge transfer process. The nanocomposites’ chromaticity coordinates for CIE 1931 color space were estimated to be (0.33, 0.34), close to pure white ones. The obtained results highlight the possibility of using these nanocomposites to achieve good performance and suitability for optoelectronic applications.

scholarly journals Fabrication of Novel 2D NiO Nanosheet Branched on 1D-ZnO Nanorod Arrays for Gas Sensor Application

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Le Thuy Hoa ◽  
Huynh Ngoc Tien ◽  
Seung Hyun Hur
Keyword(s):  
Carrier Transport ◽  
Gas Adsorption ◽  
Low Cost ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Large Area ◽  
Highly Sensitive ◽  
P Type ◽  
Reducing Gases ◽  
Nio Nanosheets

Fabrication of 3D structures composed of 1D n-type ZnO nanorods (NRs) and 2D p-type NiO nanosheets (NSs) by a low-cost, low-temperature, and large-area scalable hydrothermal process and its use in highly sensitive NO2gas sensors were studied. The p-n heterojunctions formed by NiO-ZnO interfaces as well as large area two-dimensional NiO NSs themselves increased the adsorption of NO2. Moreover, the charge transfer between NiO and ZnO enhanced the responsivity and sensitivity of NO2sensing even at a concentration of 1 ppm. The 30-min NiO NS growth on ZnO NRs in the hybrid sensor showed the highest sensitivity due to the formation of optimum p-n heterojunctions between ZnO NRs and NiO NSs for gas adsorption and carrier transport. Low responsivity toward reducing gases was also observed.

scholarly journals The Multisensor Array Based on Grown-On-Chip Zinc Oxide Nanorod Network for Selective Discrimination of Alcohol Vapors at Sub-ppm Range

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4265 ◽  
Author(s):  
Anton Bobkov ◽  
Alexey Varezhnikov ◽  
Ilya Plugin ◽  
Fedor S. Fedorov ◽  
Vanessa Trouillet ◽  
...  
Keyword(s):  
Zno Nanorods ◽  
Zno Nanorod ◽  
Proof Of Concept ◽  
Hydrothermal Route ◽  
Linear Discriminant ◽  
Practical Applications ◽  
Reasonable Degree ◽  
Highly Sensitive ◽  
On Chip ◽  
Vector Signal

We discuss the fabrication of gas-analytical multisensor arrays based on ZnO nanorods grown via a hydrothermal route directly on a multielectrode chip. The protocol to deposit the nanorods over the chip includes the primary formation of ZnO nano-clusters over the surface and secondly the oxide hydrothermal growth in a solution that facilitates the appearance of ZnO nanorods in the high aspect ratio which comprise a network. We have tested the proof-of-concept prototype of the ZnO nanorod network-based chip heated up to 400 °C versus three alcohol vapors, ethanol, isopropanol and butanol, at approx. 0.2–5 ppm concentrations when mixed with dry air. The results indicate that the developed chip is highly sensitive to these analytes with a detection limit down to the sub-ppm range. Due to the pristine differences in ZnO nanorod network density the chip yields a vector signal which enables the discrimination of various alcohols at a reasonable degree via processing by linear discriminant analysis even at a sub-ppm concentration range suitable for practical applications.

scholarly journals Effect of Growth Temperature on ZnO Nanorod Properties and Dye Sensitized Solar Cell Performance

2016 ◽  
Vol 1 ◽  
Author(s):  
Marjoni Imamora Ali Umar
Keyword(s):  
Solar Cell ◽  
Growth Temperature ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Dye Sensitized Solar Cells ◽  
Zno Nanorod ◽  
Structural Morphology ◽  
Solar Cell Performance ◽  
Dye Sensitized ◽  
Vis Spectroscopy

<p>Nanostructure of semiconductor materials zinc oxide (ZnO) is widely used in fabrication of solar cell devices. The performance of such devices is strongly depending on the nanostructures of the thin films used. In this paper reports the effect of growth temperature during synthesis of one-dimensional (1-D) anatase ZnO nanorod arrays through hydrothermal process facing their structure, morphology, and optical properties. The ZnO nanorod was first synthesized use the solution concentration and time fixed at 0.04M and 1 hour. The growth temperature were varied from 70, 80, 90 and 100 <sup>°</sup>C. The effect of growth temperature on the structural, morphology, and optical absorption of ZnO nanorod were studied by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and UV–vis spectroscopy. The regularity, diameters, heights, and surface densities of the ZnO nanorods were increased with the growth temperature.The optimum results of FESEM characterizations showed that the grown ZnO nanorods have diameters of 64.14 ± 8.3 nm, heights of 363.72 ± 34 nm and surface densities of 182 numbers/µm<sup>2</sup> which was obtained at temperature of 90 ˚C. The optimum ZnO nanorod film was utilized as photo anode in dye sensitized solar cells. The DSSC yielded Jsc of 0.86 mA/cm<sup>2</sup>, Voc of 0.49 V, and FF of 38 %, resulting in PCE of 0.16 %.</p><p> </p>

Multilayer Hybrid Structure of ZnO Nanorod Arrays Imbedded in TiO2 Network as Photoanode

2013 ◽  
Vol 1493 ◽  
pp. 111-116
Author(s):  
Chan-yan Huang ◽  
Yan Sun ◽  
Xin Chen ◽  
Ning Dai
Keyword(s):  
Electrical Properties ◽  
Electrochemical Impedance ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Hybrid Structure ◽  
Electrochemical Impedance Spectrum ◽  
Zno Nanorod ◽  
Nanorod Arrays ◽  
Zno Nanorod Arrays ◽  
Effective Electron

ABSTRACTWe developed a multilayer hybrid structure by imbedding ZnO nanorod arrays in TiO2 network for each layer, for the pourese of taking ZnO nanorods as the highway of electron transport. ZnO nanorods can be prepared by hydrothermal process, which is simple, low cost and easy control. The ZnO nanorod arrays were grown by reported hydrothermal method, then TiO2 network was constructed by spin-coating titanium precursor sol on ZnO nanorod arrays and calcining. The electrochemical impedance spectrum measurements were taken to study the electrical properties of this kind of hybrids, and the results indicated that the effective electron lifetime reaches a magnitude of microsecond which is similar to the pure ZnO nanorod arrays. It reveals to us that ZnO nanorods may dominate the electrical properties of this nano-hybrid structure.

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