Magnetically separable Z-scheme FeSiB metallic glass/g-C3N4 heterojunction photocatalyst with high degradation efficiency at universal pH conditions

Highlights: • A FeSiB metallic glass/g-C₃N₄ heterojunction photocatalyst is synthesized. • The photocatalyst facilitates dye degradation efficiently at universal pH. • The heterojunction structure improves separation efficiency of the e^- and h⁺. • The photocatalyst has high magnetic saturation to assist the recycle process. • FeSiB/g-C₃N₄ photocatalyst exhibits excellent reusability. Synthesizing efficient catalysts to degrade hazardous pollutants in wastewater, especially in alkaline conditions, is pivotal for water remediation. A magnetically separable Z-scheme FeSiB metallic glass (MG)/g-C₃N₄ photocatalyst with high activity under visible-light irradiation is prepared via ball milling. The photocatalyst exhibits a sufficient degrading capability to acid orange 7 (AO7) in acidic, neutral and alkaline solutions, and also shows excellent reusability. The photocatalytic efficiency of the composite can be optimized by modifying the weight ratio of FeSiB MG and g-C₃N₄ powders. Heterojunction structure is formed at the interface of g-C₃N₄ and FeSiB MG due to the shearing stress from ball milling, leading to the improvement of the separation efficiency of the photo-generated electron-hole pairs. This results in the enhancement in photocatalytic activity for the composite. Besides, the FeSiB MG/g-C₃N₄ photocatalyst can be recycled from solution conveniently due to their high saturation magnetization. This study offers a magnetically separable photocatalyst that can degrade azo dyes at universal pH conditions.