Solution Combustion Synthesis, Characterization, Photocatalytic Activity
and Electrochemical Studies of Yttrium Stabilised Zirconia (Zr0.72 Y0.28
O1.862) Nanopowder
Authors: Thimmanna Chandrappa Gujjarahalli , Gangadharachar Rajeshwari 
Published: September 2021

Background:
Yttria stabilized zirconia (YSZ) is an attractive material which exhibits a
characteristic combination of physical and chemical properties of YSZ in terms of inertness, resistant
to corrosion, high mechanical strength, thermal stability, chemical stability and photostability.
Because of these properties and applications, it is very important to synthesize yttrium stabilized
zirconia (YSZ) powder. Till date, various preparative techniques have been reported for the synthesis
of high porous YSZ nano powders. However, special equipment, long time with multistep processing,
high calcination temperature, small surface area and low product yield are the usual drawbacks
of most of the methods. Therefore. Solution combustion method (SCS) method has been
established for the synthesis of YSZ nanopowder with high surface area.

Objective:
The main objective of our present research work is to effectively synthesized the Yttrium
stabilized zirconia (YSZ) Zr0.72 Y0.28 O1.862 nanopowder by solution combustion method using yttrium
nitrate (Y(NO3)3.6H2O), zirconyl nitrate (ZrO(NO3)2.XH3O) as oxidizers and ethylenediamine
tetra acetic acid (EDTA) as a fuel and the synthesized powder was used in the application of photodegradation
of dyes.

Methods:
YSZ nanopowder was synthesized by using Solution combustion synthesis. Solution
combustion synthesis (SCS) is a simple exothermic self-sustaining one step chemical reaction,
which will produce a large number of pores in the oxide material and inhibit their agglomeration
leading to a large specific surface area and small crystallite size of the resulting material.

Results and Discussion:
Powder X-ray diffraction (PXRD) revealed the formation of pure cubic
phase of YSZ (Zr0.72 Y0.28 O1.862) nanopowder and the crystallite size of 15.4 nm was calculated by
using Scherrer’s formula. The porous morphology of the product was observed by SEM images.
BET surface area reveals that the relatively larger surface area of 87.17 m2g-1. TEM analysis revealed
uniform particle size distribution with average particle sizes varying in the range of 20-100
nm. The UV-Vis DRS spectrum was used to calculate the absorption wavelength (339 nm) and the
corresponding band gap (3.72 eV) using Tauc plot. The photoluminescence spectrum of YSZ
nanopowder showed an emission peak at 339 nm. The photodegradation (decolourisation) of
methylene blue (MB) dye was increased from 75-90% with increase in the concentration of YSZ
photocatalyst from 100 mg to 400 mg due to availability of OH radicals in the presence of UV radiation.
The electrochemical studies using cyclic voltammetry reveal a substantial increase in current
density of YSZ electrode from 0.0001A to 0.0005A when compared with bare carbon electrode
and the instantaneous rise in redox current for the YSZ electrodes from 0.0001A to 0.0005A with
increasing scan rate from 10 mVs-1 to 90 mVs-1.

Conclusion:
In our reported work, we start a simple and rapid solution combustion synthetic approach
to produce highly effective YSZ nanopowder using EDTA as organic fuel. Because of large
surface area and small particle size of the YSZ nanopowder shows 85% of degradation of MB
takes place in presence of UV light. In order to understand the electrochemical property of YSZ,
the redox current measurement was carried out using cyclic voltametry and resulted that increase in
redox current for the YSZ electrodes with increasing scan rate from 10 mVs-1 to 90 mVs-1.