The increasing global demand for energy and the environmental impact associated with fossil fuel consumption highlight the need for efficient electrochemical energy storage systems. In this work, a reduced graphene oxide/lanthanum hexacyanoferrate (rGO/LaHCF) nanocomposite thin film is synthesized through a single-step electrochemical deposition method. The films are characterized using electrochemical, spectroscopic, and microscopic techniques. Cyclic voltammetry reveals enhanced charge storage behavior at pH = 2.0, displaying a pseudocapacitive profile. Scanning electron microscopy shows rGO sheets coating LaHCF particles, while energy-dispersive X-ray spectroscopy confirms the expected elemental composition. Raman and FTIR analyses identify the characteristic D and G bands of rGO and the vibrational modes associated with the cyanide group of the hexacyanoferrate framework. Electrochemical measurements demonstrate specific capacitances of 81 and 26 F g− 1 at current densities of 0.5 and 10 A g− 1, respectively. Galvanostatic charge–discharge tests reveal an average coulombic efficiency of 102.8%, indicating good reversibility. During long-term cycling, the specific capacitance initially decreases within the first 180 cycles and subsequently increases, reaching approximately 110% of its initial value after 2,000 cycles. These results demonstrate that the rGO/LaHCF nanocomposite is a promising electrode material for supercapacitor applications.
Alves et al. (2026) studied this question.