In Situ Depositing Ag NPs on PDA/SiW11V Co-encapsulated Fe3O4@TiO2 Magnetic Microspheres as Highly Efficient and Durable Visible-light-driven Photocatalysts

摘要

The design and preparation of highly efficient and durable visible-light-driven photocatalysts remain a great challenge in the environment remediation. In this paper, a new multi-component composite, Fe3O4@TiO2@PDA/SiW11V-Ag, is successfully fabricated by in situ assembling Ag nanoparticles (NPs) onto polydopamine (PDA) and mono-vanadium substituted silicotungstate (SiW11VO406-, simplified as SiW11V) co-encapsulated Fe3O4@TiO2 magnetic microspheres. In the photodegradation of methyl orange (MO) and photocatalytic reduction of Cr(VI) under visible light, the multi-component composite displays the enhanced catalytic efficiency in comparison with other catalysts with less-components. Structure-reactivity relationship is established based on the correlation between photocatalytic efficiency and transient photocurrent intensity. Notably, the multi-component composite exhibits high stability and durability in wide range of pH aqueous solutions and most of organic solvents. The successful preparation of this novel type of materials provides a promising approach for constructing stable photocatalysts with multi-components, where poor compatibility of each component can be well bridged via PDA as an efficient linker and charge transport.