Uniform formation and characterization of Au/TiO2 nanoparticles for electrokinetically assisted optofluidic reactors

Abstract

Research is being conducted on photocatalyst-based organic compound treatment processes for water purification to decompose wastewater efficiently. An optofluidic reactor based on TiO₂ photocatalysis and nanoelectrokinetics was presented recently to improve the efficacy of photocatalytic water purification. However, inefficient absorption of visible light by TiO₂ materials hinders the effective utilization of solar energy. To address this issue, the uniform formation and characterization of Au/TiO₂ nanoparticles for a plasmonic photocatalytic-based optofluidic platform are studied to improve photocatalytic reactivity in visible light. The present study uses UV irradiation and spray spraying for producing Au/TiO₂ NPs uniformly on microporous carbon fabric. Energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) were used to assess the quality of the Au/TiO₂ NP-coated carbon fabric. Au NPs were uniformly obtained on the surface and inside the TiO₂ coating layer by UV irradiation-based photo-reduction, according to SEM and TEM investigation. The interaction of Au NPs, TiO₂ NPs, and carbon fabric (CF) to improve electron transport and charge separation on the photocatalyst surface is supported by XPS spectra. TEM and XRD analyses revealed that all TiO₂ components in the Au/TiO₂ coating layer consisted of anatase having high photocatalytic activity. After comparing the photocatalytic activity of TiO₂ and Au/TiO₂-coated samples under solar-simulated light and a voltage of 3 V, it was found that the surface coated with Au NPs had a superior photocatalytic effect than the surface coated with only TiO₂.