Comparative catalytic properties of Ni(OH)₂ and NiO nanoparticles towards the degradation of nitrite (NO₂¯) and nitric oxide (NO)
Date
2014Author
Adekunle, Abolanle S.
Oyekunle, John A.O.
Joshua, Abiodun O.
Ogunfowokan, Aderemi O.
Oluwafemi, Oluwatobi S.
Makinde, Wasiu O.
Eleruja, Marcus. A.
Ebenso, Eno Effiong
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Show full item recordAbstract
Nitrite (NO₂¯)
and nitric oxide (NO) have been identified as an environmentally hazardous analytes
from discharged industrial effluents. Thus in this study, nickel oxide (NiO) and nickel hydroxide
(Ni(OH)₂) nanoparticles were synthesized using the complexation
-
precipitation method and their
catalytic properties towards NO₂¯ and NO investigated. The suc
cess of the synthesised nanoparticles
was confirmed using characterisation techniques, such as X-ray diffraction (XRD), field emission
scanning electron microscopy (FESEM) and the
Fourier transformed
infrared (FTIR) spectroscopy.
The sizes of the synthesized NiO and Ni(OH)₂
nanoparticles were estimated to be 5.39 and 5.07 nm
respectively. The catalytic behaviour of NiO and Ni(OH)₂
nanoparticles towards the oxidative
degradation of NO and NO₂¯ in acidic
and neutral media respectively was studied using UV- Vis spectrophotometer. Result indicated that NiO nanoparticles demonstrated better catalytic properties at
different reaction time towards NO₂¯ and NO oxidation compared to Ni(OH)₂
, while NiO and Ni(OH)₂
at nano scale showed enhanced catalysis towards the analytes compared with the bulk Ni salt. The bulk
Ni salt did not show any sensing properties towards NO₂¯. However in NO,
the absorbance intensity
due to the generation of nitrate (NO₂¯) was five times
higher in the presence of NiO nanoparticles
compared with the bulk Ni salt. The improved catalysis of Ni(OH)₂
and NiO nanoparticles in this study
was attributed to effective pore sizes and large surface area which expose the analytes to more catalytic
site
. The nanoparticles are simple to prepare, therefore can be used for the fabrication of a simple,
portable, miniaturized nitrite and nitric oxide nanosensor for potential clinical and analytical
application.