Title:Effect of Fe Substitution on Dielectric, Electrical and Photocatalytic Behavior of ZnO Nanoparticles
VOLUME: 5 ISSUE: 1
Author(s):Umesh B. Gawas*, Rajesh M. Pednekar, Manoj M. Kothawale, Nand K. Prasad and Santosh K. Alla
Affiliation:Department of Chemistry, Dnyanprassarak Mandal’s College and Research Centre, Assagao, Goa 403 507, Department of Chemistry, Dnyanprassarak Mandal’s College and Research Centre, Assagao, Goa 403 507, Department of Physics, Dnyanprassarak Mandal’s College and Research Centre, Assagao, Goa; 403 507, Department of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221 005, Department of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221 005
Keywords:AC conductivity, DC resistivity, dielectric constant, Fe-ZnO, nanoparticles, photocatalyst, ZnO.
Abstract:
Aims: To develop a simple and cost effective synthetic strategy for the preparation of Fe
substituted ZnO nanoparticles.
Background: The optoelectronic, electrical, dielectric, optical and magnetic properties of nanocrystalline
transition metal substituted ZnO are being explored worldwide for a variety of applications in
optoelectronic devices, solar cells, transparent thin film transistors, ultraviolet photodetector, piezoelectric
devices, light emitting diodes as well as in the biomedical field. Fe substituted ZnO nanoparticles
are being looked upon as promising material in dilute magnetic semiconductor system.
Objective: To establish chemical identity and purity in order to ensure the complete substitution of
Fe3+ in ZnO lattice and study the effect of Fe substitution on dielectric, electrical and photocatalytic
behavior of ZnO nanoparticles.
Methods: The nearly spherical ZnO and Fe substituted ZnO nanoparticles were synthesized at a low
temperature via solution combustion synthesis employing metal nitrate and sucrose.
Result: The powder X-ray diffraction measurement has revealed the monophasic character and complete
substitution of Fe in the wurtzitic ZnO lattice. The lattice constants and aspect ratio of Fe substituted
ZnO were nearly constant and comparable to that of pristine ZnO. The average crystallite
size was found to decrease with increasing Fe substitution. SEM images revealed porous spongy
network like morphology. TEM measurements revealed a nearly spherical particle with narrow size
distribution between 10 nm - 25 nm.
Conclusion: The dielectric constant and dielectric loss decrease upto x = 0.04 and increases with further
increase in Fe concentration. The lower value of dielectric loss in the higher frequency region
indicates the less lossy nature of Fe substituted samples. AC conductivity behaviour suggests small
polaron hopping type of conduction mechanism. The RT DC resistivity was found to decrease with
increasing Fe substitution. Pristine ZnO displayed very high degradation efficiency for photodegradation
of MB dye. The photodegradation efficiency was found to decrease considerably with increasing
Fe substitution.
