Preparation and analysis of sol–gel-synthesized Ce(NO3)3, Ni-Ce(NO3)3, and Ni/Fe-Ce(NO3) nanoparticles for possible application in supercapacitor energy storage devices
摘要
Cerium nitrate nanoparticles, both undoped and doped with nickel, iron, and a nickel–iron composite, were successfully synthesized via the sol–gel method. The effect of metal doping on the structural, optical, and electrochemical properties of the nanoparticles was systematically examined using a range of characterization techniques. UV–visible spectroscopy revealed slight shifts in the surface plasmon resonance (SPR) peaks from 300 nm for the undoped sample to 295 nm, 298 nm, and 299 nm for the Ni−, Fe−, and Ni/Fe- doped samples, respectively, indicating changes in the electronic structure induced by doping. FTIR analysis confirmed the presence of functional groups such as hydroxyl and carboxyl groups within the spectral range of 500 to 4000 cm−1. At the same time, SEM images showed a predominantly flake-like morphology across all samples. The electrochemical performance of the synthesized nanoparticles was evaluated using cyclic voltammetry (CV), galvanostatic discharge (GCD), and electrochemical impedance spectroscopy (EIS). CV studies conducted within a potential window of − 0.3 to 0.4v at scan rates of 5–100mVs−1 revealed distinct active behavior, highlighting efficient charge storage mechanisms. EIS results showed that the iron-doped sample exhibited the highest charge-transfer resistance, attributed to ion-diffusion limitations. GCD measurements performed at current densities ranging from 0.2 to 2.0 Ag−1 within a voltage window of 0 to 0.5 V demonstrated that the nickel-doped sample delivered the highest specific capacitance of 44 F g−1 at a scan rate of 5 mV s−1. Overall, these findings demonstrate that cerium-based nanoparticles, particularly nickel-doped ones, exhibit promising electrochemical properties and are potential candidates for high-performance supercapacitor energy storage applications.