Concurrent Deposition and Exfoliation of Nickel Hydroxide Nanoflakes Using Liquid Crystal Template and Their Activity for Urea Electrooxidation in Alkaline Medium

مقال فى مجلة
Arunachalam, M. A. Ghanem, A. M. Al-Mayouf, J. P. Singh, P. . 2017
نوع عمل المنشور
Research paper
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رقم الانشاء
رقم المجلد
تاريخ المؤتمر
ملخص المنشورات

Nickel hydroxide nanoflakes (Ni(OH)2-NF) were
prepared by chemical deposition and in situ exfoliation of
nickel hydroxide layers confined in the aqueous domain of
the liquid crystalline hexagonal template of Brij®78 surfactant.
Using excess of sodium borohydride as a reducing agent
generates concurrent excessive dynamic hydrogen bubbles
which exfoliated and fragmented the nickel hydroxide layers
precipitated within the soft hexagonal template. The
physicochemical characterizations of Ni(OH)2-NF by using
surface area analyser, X-ray diffraction (XRD), XPS and
transmission electron microscope (TEM) showed the formation
of α-Ni(OH)2 nanoflakes with thickness of 2–3 nm and have
about 450m2 g−1 surface areawhich is 20 times higher than that
for bare nickel (bare-Ni) deposited without surfactant template.
The electrocatalytic activity of the Ni(OH)2-NF catalyst for urea
electrolysis was studied by cyclic voltammetry and
chronoamperometry techniques. The Ni(OH)2-NF has shown
a superior activity for the electrochemical oxidation of urea in
alkaline solution and exhibits more than tenfold increase in
activity in comparison with the bare-Ni deposit. The
enhancement of urea electrooxidation activity was related to
the superficial enhancement in the electroactive surface area
of Ni(OH)2-NF. This new approach of deposition and in situ
exfoliation by using liquid crystal template and hydrogen
bubbles offers a new platform to nanostructuring wide range
of catalysts with better catalytic performance.