In-situ fabrication of silver-modified TiO2 microspheres for enhanced visible light driven photocatalytic activities

摘要

Silver-modified TiO2 microspheres (SMTMs) have been synthesized via a novel in-situ Ag-loading method in which tetrabutyl titanate (TBOT) is hydrolyzed in a mixed solution of ethanol and AgNO3. The structures, compositions and optical properties of the as-prepared products were characterized by XRD, FT-IR, EDX, XPS, FESEM, HRTEM and UV-vis diffuse reflectance techniques, and the photocatalytic properties of the product was estimated for the photodegradation of rhodamine B (Rh B) under visible light irradiation. The photo-response of the as-obtained SMTMs is greatly shifted into the visible light spectrum, and exhibits a band gap narrowing compared with that of pure TiO2 microspheres (PT). The photocatalytic tests of SMTMs reveal a much higher photocurrent and photocatalytic activity than that of other composites and PT. However, the photocatalytic activities of SMTMs in aqueous suspension depend on the Ag-loading process. The product synthesized by using, for example, an in-situ Ag-loading process not only showed an enhanced visible light-driven photocatalytic activity, but also displayed good photocatalytic stability. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.