Cu-grafted TiO2 photocatalysts: effect of Cu on the action spectrum of composite materials

This paper describes a simple technique for the modification of titania with copper to enhance its photocatalytic performance. In addition to the absorption of UV light resulted in band-to-band excitation of electrons, TiO₂ grafted with copper species absorbs radiation in the visible region of spectrum, and it is able to completely oxidize volatile organic pollutants both under UV and visible light. The action spectra of pristine and Cu-grafted TiO₂ photocatalysts are measured and discussed to elucidate the reasons for appearance of the activity under visible light.