Surface plasmon resonance Bismuth-modified NH₂-UiO-66 with enhanced photocatalytic tetracycline degradation...

For nearly a century, the misuse of antibiotics has gradually polluted water and threatened human health. Photocatalysis is considered an efficient way to remove antibiotics from water. Zirconium-based metal-organic frameworks have attracted much attention as promising photocatalysts for the degradation of antibiotics. However, single Zirconium-based metal-organic frameworks can still not achieve a more satisfactory photocatalytic efficiency, due to poor light absorption and charge separation efficiency. In this study, a novel metal-loaded metal-organic frameworks material was explored. As a potential photocatalytic material, the performance of NH₂-UiO-66 in the photocatalytic degradation of tetracycline was greatly improved just by the loading of a single metal. Bismuth/NH₂-UiO-66 photocatalysts of various compositions were physicochemically (TEM, SEM, XRD, XPS, BET, FTIR, UV-VIS, PL), and electrochemically (electrochemical impedance spectroscopy, photocurrent response) characterized. We evaluated the photocatalytic performance of Bismuth/NH₂-UiO-66 composites by measuring their ability towards tetracycline decomposition in simulated sunlight irradiation conditions. The experimental results indicated that the introduction of metal Bismuth significantly boosts the photocatalytic activity of the composite catalysts. The final degradation rate of Bismuth/NH₂-UiO-66 for tetracycline was found to be 95.8%, namely 2.7 times higher than pure NH₂-UiO-66. This behavior is due to the surface plasmon resonance effect of Bismuth, which ameliorates the photocatalyst's electron-hole separation and strengthens the charge transfer. Apart from that, the presence of Bismuth magnifies the visible-light absorption range of Bismuth/NH₂-UiO-66. In this study, an innovative approach for designing efficient and cost-effective metal-modified metal-organic frameworks photocatalysts is proposed.