Synergistic effect of Pt0 and M2+ (Cu2+, Ni2+, Co2+) on photo(electro)catalytic activity of TiO2 nanorod array thin films

Abstract

M2+ (Cu2+, Ni2+, Co2+) and Pt0-M2+ loaded TiO2 nanorod film samples were prepared on transparent conducting oxide glass (FTO/F:SnO2). Two step method was used consisting a hydrothermal method to grow TiO2 nanorods on the surface and an ultrasonic-assisted sequential cation adsorption method to modify the nanorods. The samples were characterized by X-ray diffraction (XRD), UV–vis diffuse reflectance spectra (DRS), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy. The photoelectrochemical properties of the samples were evaluated by linear sweep voltammetry, photocatalytic activities were tested by methylene blue degradation under visible light. M2+-TiO2/FTO samples were compared with Pt0-M2+-TiO2/FTO samples; the synergistic effect of Pt0 and M2+ was discussed. Pt0-Ni2+-TiO2/FTO showed superior photoelectrocatalytic activity with 1.358 mA cm−2 and 78.3% methylene blue degradation under visible light. Quantum yields were calculated separately as a sign for H2 generation rate and as a conversion of methylene blue molecule per absorbed light.