Fe3O4:Ce@NaYF4 Core-Shell Nanocomposites: Hydrothermal Synthesis for Enhanced Magnetic, Photocatalytic and Supercapacitor Applications

A novel Fe3O4:Ce@NaYF4 core-shell nanocomposite was synthesized via a facile hydrothermal approach and comprehensively characterized for supercapacitor applications. Thermogravimetric-differential thermal analysis (TG-DTA) confirmed the thermal stability of the nanocomposite, while X-ray diffraction (XRD) verified its crystalline phase purity. The functional group composition of the nanocomposites was analyzed using Fourier-transform infrared (FT-IR) spectroscopy. The formation of well-defined core-shell nanostructures was confirmed by field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). Energy-dispersive X-ray spectroscopy (EDX) showed the uniform elemental distribution of core-shell elements. Optical properties analyzed through UV-Vis and photoluminescence (PL) spectroscopy revealed improved visible-light absorption and reduced charge recombination, resulting in enhanced photocatalytic degradation efficiency. X-ray photoelectron spectroscopy (XPS) was employed to assess the elemental composition and oxidation states, while vibrating sample magnetometry (VSM) measurement exhibited strong superparamagnetic behaviour, demonstrating the core-shell nanocomposites applicability in high-performance magnetic system. Comprehensive electrochemical analyses using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) revealed enhanced supercapacitive performance, marked by high specific capacitance and reduced charge-transfer resistance. The synergistic integration of Fe3O3:Ce@NaYF4 core-shell nanocomposite underscores its potential for environmental remediation, magnetic and energy storage applications.