Atomic Fe sites doped two-dimensional (001) TiO2 nanosheets as an effective photo-response support in methanol electro-oxidation

Abstract

The anode supports of direct methanol fuel cell (DMFC) directly affect the energy conversion efficiency between methanol fuel and electric energy. Semiconductor-based supports have nice photoelectric property for photo-assisted electrocatalytic methanol oxidation, making it be a kind of promising support of Pt. However, the rapid recombination of semiconductor photogenerated carriers limits the methanol oxidation ability of Pt. Herein, the two-dimensional (2D) (001) TiO2 nanosheets doped by a small amount of atomic iron were prepared by a reproducible impregnation method as the anode support to decrease the recombination rate. The atomic iron sites doped 2D (001) TiO2 nanosheets electrode has a high electrocatalytic performance for methanol oxidation under UV light-excitation, which is 2.7 times higher than that in dark and 4.8 times than that of non-doped electrode. The nice activities of atomic iron sites doped 2D (001) TiO2 nanosheets can be attributed to the introduction of atomic iron which are beneficial for the separation of photogeneration carriers and producing more photogenerated holes for the generation of strong oxidizing hydroxyl radicals (•OH). During the process of electrocatalytic methanol oxidation, •OH can not only promote the photocatalytic methanol oxidation, but also attenuate the inactivation of Pt poisoned by COads. These results provide a strategy to further ameliorate the photo-assisted electrocatalytic property for methanol oxidation.