Multifunctional Dy-Ce substituted BaFe12O19 hexaferrites: Enhanced supercapacitor performance, hydroelectric cell efficiency, and photocatalytic applications

In pursuit of multifunctional materials for sustainable energy and environmental applications, this study reports the synthesis and characterization of Dy-Ce co-substituted barium hexaferrites (BaDy x Ce x Fe 12-2x O 19 ) using the sol-gel auto-combustion method. This approach enables the formation of nanostructured particles with high phase purity and controlled morphology. Comprehensive analyses including X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectra, and electrochemical evaluations demonstrate that rare-earth doping introduces oxygen vacancies and lattice distortions, thereby enhancing redox activity and electrical conductivity. The optimized composition (x = 0.02) exhibits a high specific capacitance of 847.21 F/g at a scan rate of 10 mV/s, ascribed to improved pseudocapacitive behavior and defect-mediated charge transport. Hydroelectric cell performance for the same composition yields a maximum open-circuit voltage of 1.05 V and a short-circuit current of 30 mA, validating the role of defect-engineered surfaces in promoting efficient water dissociation and ionic conductivity. Additionally, the photocatalytic degradation of methylene blue (10 ppm) under solar irradiation achieves a degradation efficiency of 83.1% within 200 min at neutral pH, underscoring the material's utility for environmental remediation. The synergistic effects of Dy 3+ and Ce 4+ co-doping via mixed valence states, ionic size disparities, and resultant oxygen vacancy formation collectively contribute to superior electrochemical and photocatalytic properties. These findings establish Dy-Ce substituted BaFe 12 O 19 hexaferrites as promising candidates for integrated energy storage, hydroelectric power generation, and wastewater treatment systems. • High supercapacitor performance with 847.21 F/g specific capacitance at 10 mV/s. • Hydroelectric output of 1.05 V open-circuit voltage and 30 mA short-circuit current through enhanced oxygen vacancy generation. • 83.1% photocatalytic degradation of methylene blue under solar irradiation. • Strong charge stability, retaining 84% capacitance after 5000 cycles.