Photocatalytic Degradation of Rhodamine B Dye by TiO₂ and Gold Nanoparticles Supported on a Floating Porous Polydimethylsiloxane Sponge under Ultraviolet and Visible Light Irradiation

Abstract

A combination of plasmonic nanoparticles (NPs) with semiconductor photocatalysts, called plasmonic photocatalysts, can be a good candidate for highly efficient photocatalysts using broadband solar light because it can greatly enhance overall photocatalytic efficiency by extending the working wavelength range of light from ultraviolet (UV) to visible. In particular, fixation of plasmonic photocatalysts on a floating porous substrate can have additional advantages for their recycling after water treatment. Here, we report on a floating porous plasmonic photocatalyst based on a polydimethylsiloxane (PDMS)−TiO 2 −gold (Au) composite sponge, in which TiO 2 and Au NPs are simultaneously immobilized on the surface of interconnected pores in the PDMS sponge. This can be easily fabricated by a simple sugar-template method with TiO 2 NPs and in situ reduction of Au NPs by the PDMS without extra chemicals. Its ability to decompose the organic pollutant rhodamine B in water was tested under UV and visible light, respectively. The results showed highly enhanced photocatalytic activity under both UV and visible light compared to the PDMS−TiO 2 sponge and the PDMS−Au sponge. Furthermore, its recyclability was also demonstrated for multiple cycles. The simplicity of fabrication and high photocatalytic performance of our PDMS−TiO 2 −Au sponge can be promising in environmental applications to treat water pollution.

Plasmonic Gold Nanoparticles (AuNPs): Properties, Synthesis and their Advanced Energy, Environmental and Biomedical Applications

“…The plasmonic AuNPs extended the solar absorption wavelength from ultraviolet (UV) to visible range, when incorporated in semiconductor oxides such as TiO 2 and ZnO. [125][126][127][128] For example, a polydimethylsiloxane (PDMS)-TiO 2 -Au composite sponge, where the AuNPs and TiO 2 simultaneously immobilized the sponge pores. This arrangement induces superior solar absorption and floating characteristics in the photocatalyst, which improved the dye degradation performance.…”

“…The photocatalytic removal of waste treatment is a well‐known technology, and AuNPs can be one of the potential applicants for these applications due to sufficient optoelectrical characteristics. The plasmonic AuNPs extended the solar absorption wavelength from ultraviolet (UV) to visible range, when incorporated in semiconductor oxides such as TiO 2 and ZnO [125–128] . For example, a polydimethylsiloxane (PDMS)‐TiO 2 ‐Au composite sponge, where the AuNPs and TiO 2 simultaneously immobilized the sponge pores.…”

Recent Advances on Plasmon-enhanced Titania Nanocatalysts for Photocatalytic Degradation of Organic Dyes

“…The SPR causes a strong absorption of the incident light in the UV and visible light regions; thus, detectable by the UV-Vis spectrometer. In recent years, supported Au NPs have attracted significant attention as the heterogeneous catalyst for the photocatalytic decomposition of organic pollutants in the aqueous environment [43][44][45][46][47]. Among various supports, TiO2 has shown notable photocatalytic activity towards the degradation and mineralization of organic pollutants.…”

Facile synthesis of a high purity α-MnO2 nanorod for rapid degradation of Rhodamine B

“…Recently, much effort has been focused on the degradation of dyes by semiconductor photocatalyst. In pursuit of low cost, non-toxicity and chemical stability, titanium dioxide (TiO 2 ) shows good application as a photocatalyst [6,7]. However, TiO 2 can only absorb ultraviolet (UV) light in the solar spectrum, which greatly limits the application of TiO 2 in photocatalytic degradation.…”