Abstract
The accumulation of organic micropollutants in aquatic environments poses a severe threat to ecosystems and human health. Traditional water treatment methodologies are often ineffective against these recalcitrant compounds, necessitating the development of advanced oxidation technologies. In this study, we report the fabrication of highly ordered titanium dioxide nanotube arrays (TiO2 TNAs) via electrochemical anodization, subsequently decorated with silver (Ag) nanoparticles through a photo-assisted deposition method. The localized surface plasmon resonance (LSPR) of the Ag nanoparticles significantly shifts the optical absorption edge of the TiO2 TNAs from the ultraviolet into the visible-light region. The morphology, crystalline structure, optical absorption, and charge-carrier dynamics of the synthesized Ag-decorated TNAs (Ag/TNAs) were systematically characterized. Photocatalytic performance evaluation revealed that the Ag/TNAs exhibited exceptional visible-light activity, achieving a 96.4% degradation efficiency of sulfamethoxazole (SMX) within 120 minutes, which is more than ten times higher than that of pristine TNAs. This enhanced performance is attributed to the synergistic effect of the 1D nanotubular architecture, which provides direct pathways for electron transport, and the LSPR effect of the Ag nanoparticles, which facilitates hot-electron injection and suppresses electron-hole recombination. Radical scavenger experiments confirmed that superoxide radicals (•O2-) and photogenerated holes (h+) are the primary active species driving the degradation process. This work highlights the potential of plasmonic-enhanced nanostructured catalysts for energy-efficient environmental remediation.
