TiO2@Sn3O4 nanorods vertically aligned on carbon fiber papers for enhanced photoelectrochemical performance.

ABSTRACT

Semiconductor heterostructures are regarded as an efficient way to improve the photocurrent in photoelectrochemical cell-type (PEC) photodetectors. To better utilize solar energy, TiO2@Sn3O4 arrays vertically aligned on carbon fiber papers were synthesized via a hydrothermal route with a two-step method and used as photoanodes in a self-powered photoelectrochemical cell-type (PEC) photodetector under visible light. TiO2@Sn3O4 heterostructures exhibit a stable photocurrent of 180 µA, which is a 4-fold increase with respect to that of the Sn3O4 nanoflakes on carbon paper, and a two-order increase with respect to that of the TiO2 NRs arrays. The evolution of hydrogen according to the photo-catalytic water-splitting process showed that Sn3O4/TiO2 heterostructures have a good photocatalytic hydrogen evolution activity with the rate of 5.23 µmol h-1, which is significantly larger than that of Sn3O4 nanoflakes (0.40 µmol h-1) and TiO2 nanorods (1.13 µmol h-1). Furthermore, the mechanism behind this was discussed. The detector has reproducible and flexible properties, as well as an enhanced photosensitive performance.