Electrospun Pt/TiO2 hybrid nanofibers for visible-light-driven H2 evolution.

One-dimensional (1D) Pt/TiO 2 hybrid nanofibers (HNFs) with different concentrations of Pt were fabricated by a facile two-step synthesis route combining an electrospinning technique and calcination process. X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) results showed that the Pt nanoparticles (NPs) with the size of 5–10 nm were well dispersed in the TiO 2 nanofibers (NFs). Further investigations from the UV–Vis diffuse reflectance (DR) and X-ray photoelectron spectroscopy (XPS) analysis revealed that some Pt ions were incorporated into the TiO 2 lattice as Pt 4+ state, which contributed to the visible light absorption of TiO 2 NFs. Meanwhile, the Pt 2+ ions existing on the surface of Pt NPs resulted in the formation of Pt–O–Ti bond at Pt NPs/TiO 2 NFs interfaces that might serve as an effective channel for improving the charge transfer. The as-electrospun Pt/TiO 2 HNFs exhibited remarkable activities for photocatalytic H 2 evolution under visible light irradiation in the presence of l -ascorbic acid as the sacrificial agent. In particular, the optimal HNFs containing 1.0 at% Pt showed the H 2 evolution rate of 2.91 μmol h −1 and apparent quantum efficiency of 0.04% at 420 nm by using only 5 mg of photocatalysts. The higher photocatalytic activity could be ascribed to the appropriate amount of Pt ions doping and excellent electron-sink effect of Pt NPs co-catalysts. [ABSTRACT FROM AUTHOR]