Effect of solution molarity on the structural properties of ZnO nanopowder synthesized by
microwave-assisted hydrothermal synthesis
Zinc oxide (ZnO) is an important multifunctional material with extensive applications in
electronics, photoelectronics [1], sensors [2], and optical devices [3]. Especially for the application
of gas sensors is preferred porous microstructure materials such as ZnO due to controlling pore
size [4]. Additionally, ZnO is an impressive potential semiconductor with a direct wide band gap
(3.37 eV), a large exciton binding energy of 60 meV, and excellent chemical and thermal stability
[5].
To date, remarkable efforts have been dedicated to fabricate different ZnO nanostructures,
including nanoflowers [6], nanorods [5], nanosheets [7] and so on, because of their strong size or
morphology-dependent properties or device performances. ZnO nanopowder have been
synthesized by many methods such as microwave-assisted hydrothermal synthesis [8],
hydrothermal method [9] and vapor transport process [10]. Compared with conventional
hydrothermal method, microwave hydrothermal synthesis has attracted wide interests due to its
unique effects such as energy saving, higher reaction rates, rapid volumetric heating, low reaction
temperature, homogeneous thermal transmission, higher selectivity and higher yields of products.
In the present study, ZnO nanopowders were synthesized by microwave-assisted
hydrothermal method at different molarities (0.1M-0.4M) of zinc acetate dihydrate. The effects of
solution molarity on the structural and morphological properties of ZnO nanopowders were
investigated by using X-ray diffraction (XRD) and field emission scanning electron microscopy
(FE-SEM), respectively. XRD results showed that all the ZnO nanopowders are in crystalline form
with hexagonal wurtzite phase and high purity. The crystallite size and texture coefficient values
of ZnO nanopowders were calculated. The intensity of peaks of ZnO nanopowders gradually
increased with the decreasing molarity. Also, a significant effect on the surface morphology was
observed because of the variation of solution molarity.
Acknowledgement
This work was supported by Anadolu University Commission of Scientific Research Project under
Grant no. 1306F243.
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