Insights into the piezo-photocatalytic activity and optimized magnetic recovery of hybrid bismuth ferrite-based nanosystems

Bismuth ferrite (BiFeO₃), a perovskite oxide with both ferroelectric and antiferromagnetic properties, has emerged as a promising material for environmental cleanup due to its piezo-photocatalytic activity. The material's ability to degrade organic pollutants, such as azo dyes, under both light irradiation and mechanical stress (ultrasonic waves) offers a dual-action mechanism for efficient wastewater treatment. In this work, we explore the synthesis of BiFeO₃ nanoparticles <i>via</i> a simple sol-gel method, followed by characterization of their structural, magnetic, and photocatalytic properties. Under ultrasonic treatment, BiFeO₃ generates piezoelectric potentials that enhance electron-hole separation, promoting photocatalytic degradation of methylene blue. The combination of photocatalysis and piezocatalysis improves catalytic efficiency while reducing energy consumption compared to traditional UV-based photocatalysis. Additionally, coupling BiFeO₃ with cobalt ferrite (CoFe₂O₄) creates a magnetically recoverable system, facilitating efficient catalyst separation from treated water, and modifying the kinetic process of photodissociation. The magnetic recovery was improved through the development of a tailored magnetic support system, designed to optimize the spatial magnetic field gradient. These findings highlight the potential of BiFeO₃-based nanosystems for sustainable, energy-efficient, and eco-friendly solutions to water pollution, addressing both dye degradation and the need for effective water remediation techniques.