Breakthrough in wastewater treatment: bismuth ferrite-based piezo-photocatalysis for dye degradation

 Traditional wastewater treatment methods for dye wastewater often fall short in effectively removing organic dyes from water bodies.

The research team, led by Dr. Liu Baojiang, synthesized Bi₂Fe₄O₉ nanosheets using a hydrothermal method. This material, known for its piezoelectric properties and narrow bandgap, was tested for its ability to degrade reactive dye KN-R under ultrasonic and visible light conditions. The results were remarkable: the degradation efficiency of KN-R reached 98.5% under optimal conditions (pH of 3 and a dye concentration of 60 mg/L), with the piezo-photocatalytic process being 3.4 times more efficient than piezoelectric catalysis alone and 2.6 times more efficient than photocatalysis alone.

The study also explored the impact of various factors on the degradation process. Importantly, Bi₂Fe₄O₉ demonstrated excellent recyclability, maintaining high degradation efficiency over multiple cycles.

The innovation lies in the synergistic effect of piezoelectric and photocatalytic processes. The piezoelectric effect modulates the energy band structure of Bi₂Fe₄O₉, promoting the separation of photogenerated electron-hole pairs and enhancing the generation of reactive species like hydroxyl radicals (·OH) and superoxide radicals (·O₂). This dual-action mechanism significantly boosts the degradation of organic dyes.

This innovative approach not only offers an effective solution for treating dye wastewater but also highlights the potential of Bi₂Fe₄O₉ as a sustainable and eco-friendly material for environmental applications. The work entitled “Piezo-photocatalytic technology based on bismuth ferrite (Bi₂Fe₄O₉) for degradation of reactive dye KN-R” was published in Journal of Donghua University (English Edition) (published on Feb. 28, 2025).