Research PaperSurface plasmon resonance-enhanced solar-driven photocatalytic performance from Ag nanoparticle-decorated self-floating porous black TiO2 foams

- Ag nanoparticle-decorated self-floating porous black TiO2 foams (Ag-FBTFs) are fabricated.
- Small Ag nanoparticles of 3-4 nm are formed due to confinement effect.
- It extends the photoresponse to visible-light region and show obvious surface plasmon resonance (SPR).
- The Ag-FBTFs exhibit excellent solar-driven photocatalytic performance.
- It ascribes to floating feature and SPR favoring light-harvesting and spatial charge separation.

Ag nanoparticle-decorated self-floating porous black TiO2 foams (Ag-FBTFs) are fabricated by facile wet-impregnation and high-temperature surface hydrogenation strategy, utilizing self-floating porous black TiO2 foams (FBTFs) with 3D macro-mesoporous architectures as hosts. The composites are evidently investigated by X-ray diffraction (XRD), Raman, N2 adsorption, diffuse reflectance spectroscopy (DRS), transmission electron microscope (TEM), scanning electron microscopy (SEM), scanning Kelvin Probe (SKP), surface photovoltage spectroscopy (SPS) and photoluminescence (PL). The results show that the small Ag nanoparticles with diameter of 3-4 nm are decorated on the surface of FBTFs uniformly, which extend the photoresponse to visible-light region and show obvious surface plasmon resonance (SPR). The Ag-FBTFs exhibit excellent solar-driven photocatalytic performance for complete mineralization of some high-toxic organic contaminants. The enhancement can be attributed to the 3D macro-mesoporous networks facilitating the diffusion of reactants and products, the floating feature and small Ag nanoparticle-decoration favoring light-harvesting and spatial separation of photogenerated electron-hole pairs due to SPR effect. This novel SPR-enhanced solar-driven floating photocatalyst will have potential application in fields of natural environment.

Ag nanoparticle-decorated self-floating porous black TiO2 foams are fabricated via wet-impregnation combined with high-temperature hydrogen reduction strategy, which narrow the bandgap and exhibit excellent solar-driven photocatalytic performance due to the floating feature and surface plasmon resonance of Ag nanoparticles enhancing light-harvesting and spatial separation of photogenerated charge carriers.181