Recyclable visible-light photocatalytic composite materials based on tubular Au/TiO2/SiO2 ternary nanocomposites for removal of organic pollutants from water

The highly active free radicals generated by semiconductor materials in the photocatalytic technology can achieve efficient degradation of organic pollutants. Tubular Au/TiO2/SiO2 ternary nanocomposite is fabricated under high-temperature ablation via the sacrificial template and noble metal deposition. SiO2 is deposited to inhibit the growth of grain size of TiO2. The tubular structure can effectively increase the scattering times and improve the utilization of visible-light. Au nanoparticles (Au NPs) absorb visible-light and promote the formation of photogeneration-hole pairs. Besides, Au NPs can also be used as an electron acceptor to delay the recombination rate of photogeneration electron-hole pairs, and improve the photocatalytic activity. Furthermore, the polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) gel was used to load and immobilize TiO2-based catalytic materials, and the composite gel still has a good photocatalytic activity with favorable cyclability. This work opens up a new opportunity for designing the photocatalytic composite material with long-term catalytic stability and excellent reusability.