Gold nanoparticle-deposited reduced dendritic fibrous nanotitania for enhanced photocatalytic performance

In recent decades, extensive research has focused on developing titania for photocatalysis, photovoltaics, and energy storage. Metal doping, electronic structure modification, and morphological design are effective strategies to enhance the performance of titania for these applications. In this study, we report the fabrication of hybrid nanostructures of gold nanoparticles (AuNPs) anchored on reduced dendritic fibrous nanotitania (R-DFNT) (Au/R-DFNT) via a chemical reduction method. The hierarchical structure of R-DFNT not only facilitates rapid mass transport but also maximizes the exposure of abundant defect species as nucleation sites for anchoring gold nucleation, resulting in well-dispersed AuNPs on R-DFNT. The photocatalytic performance of Au/R-DFNT nanocomposites is evaluated through the photodegradation of ciprofloxacin (CP). The optimized Au/R-DFNT sample exhibits outstanding photocatalytic activity towards CP degradation, with a kinetic rate constant of 0.0111 min^-1, which is 2.3, 25.5, and 4.1 times higher than those of pristine R-DFNT, reduced commercial P25, and the AuNPs/reduced-P25 nanocomposite, respectively. The superior photocatalytic efficiency of Au/R-DFNT is mainly attributed to its dendritic fibrous morphology, the abundance of exposed defect sites, and the well-formed gold-titania heterojunction, which facilitates charge-transfer and prolongs the lifetime of charge carriers.