Assessing the photoelectrochemical properties of C, N, F codoped TiO2 nanotubes of different lengths. - Chatzitakis, Athanasios; Grandcolas, Mathieu; Kaiqi Xu; Sen Mei; Juan Yang; Thue Jensen, Ingvild Julie; Simon, Christian; Norby, Truls (Catalysis Today, 2017)