TiO 2 @Sn 3 O 4 nanorods vertically aligned on carbon fiber papers for enhanced photoelectrochemical performance.

Semiconductor heterostructures are regarded as an efficient way to improve the photocurrent in photoelectrochemical cell-type (PEC) photodetectors. To better utilize solar energy, TiO 2 @Sn 3 O 4 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. TiO 2 @Sn 3 O 4 heterostructures exhibit a stable photocurrent of 180 μA, which is a 4-fold increase with respect to that of the Sn 3 O 4 nanoflakes on carbon paper, and a two-order increase with respect to that of the TiO 2 NRs arrays. The evolution of hydrogen according to the photo-catalytic water-splitting process showed that Sn 3 O 4 /TiO 2 heterostructures have a good photocatalytic hydrogen evolution activity with the rate of 5.23 μmol h -1 , which is significantly larger than that of Sn 3 O 4 nanoflakes (0.40 μmol h -1 ) and TiO 2 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.