Abstract: Phthalocyanine-sensitized TiO2 sol samples were prepared through a sol-gel method using copper(Ⅱ) phthalocyanine tetrasulfonic acid (CuPcTs) as a sensitizer. Phthalocyanine-sensitized TiO2 (CuPcTs-TiO2) film samples were obtained from the as-prepared TiO2 sol by a dip-coating technique at room temperature. XRD, UV-Vis, and SEM were adopted to characterize the samples, and the degradation of rhodamine B was employed as the model reaction to evaluate the photocatalytic activity of CuPcTs-TiO2 film under the visible light. The results indicated that the TiO2 film is composed of the anatase-brookite-rutile mischcrystal phase, and thus the CuPcTs-TiO2 film samples have higher catalytic activity. The sensitization of CuPcTs can enhance visible-light catalytic activity of the TiO2 film, but too much CuPcTs can decrease its catalytic activity. Under the visible light illumination, rhodamine B first turns into rhodamine via the N-de-ethylation, and the intermediate product is subsequently degraded. The catalytic activity of the CuPcTs-TiO2 film samples becomes stable after being used2-3times. The preparation method is favorable for the firm loading of CuPcTs in TiO2 film, and thus ensures the stability for repeated use of the CuPcTs-TiO2 film.

Key words: copper(Ⅱ) phthalocyanine tetrasulfonic acid, sensitization, titania, low-temperature preparation, rhodamine B, degradation, photocatalysis, visible light