Characterization of Co-AC/TiO2 Composites and Their Photonic Decomposition for Organic Dyes

Abstract

In this study, activated carbon (AC) as a carbon source was modified with different concentrations of cobalt chloride (CoCl 2 ) to prepare a Co-AC composite, and it was used for the preparation of Co-AC/TiO 2 composites with titanium oxysulfate (TOS) as the titanium precursor. The physicochemical properties of the prepared Co-AC/TiO 2 composites were characterized by N 2 adsorption at 77 K, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. The photocatalytic treatments of organic dyes were examined under an irradiation of visible light with different irradiation times. N 2 adsorption data showed that the composites had decreased surface area compared with the pristine AC, which was 389 m 2 /g. From the XRD results, the Co-AC/TiO 2 composites contained a mixturephase structuresof anatase and rutile, but a cobalt oxide phase was not detected in the XRD pattern. The EDX results of the Co-AC/TiO 2 composites confirmed the presence of various elements, namely, C, O, Ti, and Co. Subsequently, the decomposition of methylene orange (MO, C 14 H 14 N 3 NaO 3 S) and rhodamine B (Rh.B, C 28 H 31 ClN 2 O 3 ) in an aqueous solution, respectively, showed the combined effects of an adsorption effect by AC and the photo degradation effect by TiO 2 . Especially, the Co particles in the Co-AC/TiO 2 composites could enhance the photo degradation behaviors of TiO 2 under visible light.