▎ 摘　　要

The photocatalytic properties of TiO2 nanotubes (NTs) modified by copper nanoparticles (NPs) and (reduced) graphene oxide ((r)GO) are herein evaluated. The hybrid TiO2 nanomaterials were deeply characterized by means of N-2 adsorption-desorption measurements, X-ray diffraction, X-ray photoelectron and UV-vis diffuse reflectance spectroscopies, and transmission electron microscopy. On Cu/TiO2 NTs, results show a stabilization of Cu NPs at a +I oxidation state due to a strong interaction with TiO2 NTs leading to an 80% increase in activity for formic acid (FA) degradation under UV irradiation. Contrary to GO/TiO2 NTs, in the presence of Cu, addition of non-reduced GO leads to a 150% increase in activity compared to its free counterpart Cu/TiO2 NTs while the use of partially reduced GO leads to a complete loss of any beneficial effect due to graphene oxide.