Effect of Hydrothermal reaction times and temperature-dependent Spherical like NiCo2O4 nanoparticles for supercapacitor application

ABSTRACT

 The effects of reaction times and temperatures on the electrochemical capacitance characteristics of NiCo₂O₄ nanoparticles (NPs) are investigated. The hydrothermal reaction temperatures and times play critical parts in the creation of unique hierarchical NCO based on morphological evolution in this work. The calcination temperature 400 °C was fixed using TG-DTA study. The crystal structure and phase identification is investigated from XRD analysis. FTIR peaks in the region of 700-500 cm⁻¹ confirmed the presence of the Ni-O and Co-O bond. The spherical-like nanostructure NiCo₂O₄ particles are visualized from SEM, HR-SEM and HR-TEM analyses. From the EDS spectra, the atomic percentage composition of the elements namely, Ni, Co and O were observed. The optimized sample was subjected to a VSM and CV analyses, which revealed that it is superparamagnetic nature (Ms = 4.8298 emu/g) and Pseudocapacitive behaviour with highest capacitance value of 534 Fg⁻¹ with the lower scan rate of 10 mVs⁻¹.

KEYWORDS:

• Hydrothermal method
• spherical-like NCO NPs
• supercapacitor application

Highlights

1. The XRD analysis confirmed that the prepared NCO nanoparticles are cubic crystal structure.

2. The optimized NCO-D sample HR-SEM and HR-TEM reveals the synthesized product is spherical structure.

3. VSM study reveals the NCO-D sample shows superparamagnetic nature.

4. The specific capacitance value is 534 Fg⁻¹, which shows the specific capacitance of NCO-D sample suitable for supercapacitor application.

Acknowledgments

The authors gratefully acknowledge the Centralized Instrumentation and Service Laboratory (CISL), Annamalai University, Annamalainagar, Tamil Nadu, India, for providing excellent research facilities and support for a part of Ph.D research work of one of the authors.

Disclosure statement

No potential conflict of interest was reported by the author(s).