Structural and Electrochemical Response of Hydrothermally Engineered Hierarchical ZnO Nanoarchitectures
1.
Ravi Kumar Modi
– School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology, Bhubaneswar, Odisha, India.
2.
Sushree Subhadarsi Bhole
– School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology, Bhubaneswar, Odisha, India.
3.
Smruti Sikha Sahoo
– School of Basic Science, Indian Institute of Technology, Bhubaneswar, Odisha, India.
4.
N. Tamilselvan
– Department of CSBS, M.Kumarasamy College of Engineering, Karur, Tamil Nadu, India.
5.
Shree Kesavan Kannan
– School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology, Bhubaneswar, Odisha; Department of Chemistry, M.Kumarasamy College of Engineering, Karur, Tamil Nadu, India.
Received -
Accepted -
Published 25-Jun-2026
Abstract
Hierarchical ZnO nanoarchitectures were prepared by hydrothermal crystallization using zinc nitrate and hexamethylenetetramine as precursors. The diffraction pattern corresponded to hexagonal wurtzite ZnO, with no additional crystalline phase detected within the measured range. Electron microscopy revealed aggregates composed of interconnected plate-like crystallites, while energy-dispersive X-ray spectroscopy detected Zn and O in the examined region. The electrochemical response was studied in a three-electrode configuration using 3 M KOH through cyclic voltammetry and electrochemical impedance spectroscopy. The voltammograms retained comparable profiles between 100 and 300 mV s-1, with increasing current and moderate peak displacement at higher scan rates. The Nyquist spectrum contained a short high-frequency arc followed by a steep low-frequency branch, showing distinct frequency-dependent contributions to the electrode response. Electron microscopy revealed interparticle spaces within the plate-based architecture, providing a structural basis for contact with the electrolyte. The study describes the structural and electrochemical performance of hierarchical ZnO in an alkaline medium without compositional modification.
