Sol-gel synthesized Ni-Cu-Fe-Cr spinel ferrite with experimental and computational insights for photocatalytic methylene blue degradation

초록

This research presents an experimental and theoretical analysis of Ni0.75Cu0.25Fe1.5Cr0.5O4 spinel ferrite, synthesized by sol-gel auto-combustion, concerning the photocatalytic degradation of methylene blue. The calculated lattice values are 8.31 & Aring; (experimental) and 8.35 & Aring; (theoretical), and a crystalline size of 26 nm. The material exhibits strong absorption, with energy band gap values of 1.42 eV (experimental) and 1.393 eV (theoretical), confirming its semiconductor nature. In photocatalytic tests under visible light, it achieved 92% degradation of MB within 120 min, following pseudo-first-order kinetics with a rate constant of 0.04758 min- 1. A maximum specific surface area of 42 m2/g enhances the availability of reactive sites and promotes charge separation. FTIR spectra exhibited absorption bands at 523 cm-1 and 464 cm- 1. SEM analysis revealed spherical grains with good crystallinity and some agglomeration. These results suggest that Ni0.75Cu0.25Fe1.5Cr0.5O4 is a promising photocatalyst for environmental cleanup, demonstrating effective light absorption and charge separation capabilities.

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