Core–shell BiVO₄@PDA composite photocatalysts on cotton fabrics for highly efficient photodegradation under visible light

Highly efficient and reusable photocatalysts that enable photodegradation of pollutants under visible light is the key in waste water treatment with impacts on environment and sustainable development. In this article, we report the preparation and application of a novel core–shell photocatalyst of bismuth vanadate@polydopamine (BiVO₄@PDA). The optical absorption property and microstructure of the BiVO₄@PDA particles were measured by ultraviolet–visible spectrophotoscopy (UV–Vis), photoluminescence (PL) spectroscopy and transmission electron microscope. The BiVO₄@PDA can be attached to cotton fabrics by electrostatic assembly and molecular bonding. The morphology and structure of the cotton fabric@BiVO₄@PDA were characterized by SEM, X-ray photoelectron spectroscopy and X-ray diffraction. The photocatalytic activity results show that the methylene blue (MB) can be completely degraded by BiVO₄@PDA under visible light irradiation within 250 min. Moreover, the mechanism for the MB photodegradation using the cotton fabric@BiVO₄@PDA photocatalyst under visible light were investigated. With the novel core–shell structure, the as-developed BiVO₄@PDA particles can be used as highly efficient photocatalysts for visible light driven photodegradation. The BiVO₄@PDA particles can be attached to different substrates due to the excellent adhesive and bonding nature of PDA towards high-efficient photocatalysis.