Visible-Light Self-Powered Photodetector and Recoverable Photocatalyst Fabricated from Vertically Aligned Sn3O4 Nanoflakes on Carbon Paper

Self-powered photodetectors (SPPDs) are promising candidates for high-sensitivity and high-speed applications because they do not require batteries as an external power source. It is a challenge to fabricate visible-light photodetectors. Herein, vertically aligned two-dimensional (2D) Sn3O4 nanoflakes on carbon fiber paper were prepared by a modified hydrothermal approach and used as a self-powered photoelectrochemical cell-type visible-light detector. The detector exhibits reproducible and flexible properties as well as an enhanced photosensitive performance. The improved photoresponse was attributed to the synergistic effects of the vertically grown Sn3O4 nanoflakes and carbon fiber paper substrate; the former provided efficient active sites, as it exposed more catalytic sites to the electrolyte and absorbed more light scattered among the nanoflakes, and the latter benefited charge transport. The photocatalytic activity of the three-dimensional (3D) Sn3O4 hierarchal structure on rhodamine B under visible-light irradiation was investigated and shown to have a degradation rate constant of 3.2 x 10(-2) min(-1).The advantage over ordinal materials for use in an SPPD device is that this material is flexible and easily recoverable as a photocatalyst.