Investigation On The Properties Of Nanostructured Nickel Oxide Layer For Hydrogen Gas Sensor
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Date
2018-03
Authors
Abubakar, Dauda
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
In this work, nanostructured NiO layers were synthesized using chemical
bath deposition (CBD) and thermal oxidation methods for high performance of H2
gas sensor. The synthesis of nanostructured NiO layer was controlled base on several
growth parameters which were varied in each deposition methods. The structural,
morphological, and optical properties of nanostructured NiO layer were studied
using XRD, FESEM, EDX and UV-Vis spectrometer. The crystal size, surface
roughness, porous surface, layer thickness, and crystallinity are factors that have
great influence in enhancing the H2 gas sensing performance. These factors are the
main reason why most report on NiO for H2 gas sensor shows poor sensing
performance. Thus, the focus of this report is to enhance the H2 gas sensing
performance base on these factors. The nanostructured NiO layer samples that were
grown at 300 0C (CBD) and 550 0C (thermal oxidation) on ITO/glass substrates
show good results needed for improving H2 gas sensing performance and used as the
sensing membranes for H2 gas sensor. The H2 gas sensing properties of
nanostructured NiO layer were studied based on the H2 gas concentration and
operating temperature. It was observed that the H2 gas response (sensitivity)
decreases with increase in operating temperature due to high humidity (i.e. 80 %)
at low temperatures (i.e. 25 0C) that increases the resistance. The effect of humidity
decreases with temperature resulting in decreasing the resistance. The CBD base
sample shows higher H2 gas response (i.e. 50.44) at RT (25 0C) than thermal
oxidation base sample (i.e. 3.12) due to its smaller crystal size (i.e. 19.84 nm), higher
roughness (i.e. 75.2 nm), higher pore size (i.e. 300 nm) and higher layer thickness
(i.e. 683.7 nm). Likewise, the power consumption at RT (25 0) of the CBD sample is
lower (i.e. 0.13 mW) than thermal oxidation sample (i.e. 2.7 mW) due to the
response of the CBD sample at higher resistance (i.e. 1975 ).
Description
Keywords
Properties of nanostructured nickel oxide layer , for hydrogen gas sensor