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

Abstract

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) Sn 3 O 4 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 Sn 3 O 4 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) Sn 3 O 4 hierarchal structure on rhodamine B under visible-light irradiation was investigated and shown to have a degradation rate constant of 3.2 × 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.

SnO x @β–SnO heterostructures and their enhanced photocurrent in photoelectrochemical cell

“…The maximal photocurrent density of Sn-2 is over 200 μA cm −2 , about four times larger than that of sample Sn-1. This value is much larger than ever reported self-powered photodetectors (SPPDs) [28], 75 μA cm −2 in SnO x [29] and 60 μA cm −2 in Sn 2+ -SnO 2 composites [30]. To investigate the changes of the electrochemical specific surface area, the difference in current density variation plotted against scan rate is shown in figure 4(b).…”

Hierarchical TiO2 Photoanodes with Spatial Charge Separation for Efficient Oxygen Evolution Reaction

“…[ 25,26 ] It is clear that O 1s contains three oxygen peaks (Figure 2D), in which O1 at around 530 eV is the lattice oxygen from TiO 2 and Sn 3 O 4 (529.9 eV for OTi or OSn 2+ and 530.4 eV for O‐Sn 4+ ), O2 (531.6 eV) is associated with the hydroxyl groups, and O3 (532.4 eV) is attributed to the oxygen defect species. [ 27–29 ] It is clear that the area ratio of O3 in Sn 3 O 4 /TiO 2 /Au is larger than that in TiO 2 /Au (Figure S7B, Supporting Information), illustrating the abundant catalytic active sites in Sn 3 O 4 cocatalyst. Thereby, it can be concluded that the TiO 2 nanorods were successfully decorated with 2D Sn 3 O 4 nanoflake cocatalysts.…”

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

“…Sn 3 O 4 nanoakes (NFs) were prepared on the carbon ber papers by a modied hydrothermal approach, which is similar to the reported in our previous study. 26 In detail, 1.073 g of SnCl 2 $2H 2 O and 2.940 g Na 3 C 6 H 5 O 7 $2H 2 O were dissolved in the mixture of 20 mL de-ionized water and 20 mL alcohol under constant magnetic stirring for approximately 60 min. The obtained homogeneous solution was transferred into a Teon liner of 50 mL capacity with the carbon ber paper vertical immersed into the reaction solution and keeping sealed under 180 C for 18 h. Aer the reaction, the carbon ber paper coated with a brown product was further washed with deionized water and absolute ethanol for several times.…”

“…The energy band of Sn 3 O 4 NFs has been discussed previously. 22 Then, the conduction band and valence band (vs. vacuum) of TiO 2 NRs and Sn 3 O 4 NF scan be obtained, as shown in Table 1.…”

“…20 Recently, self-powered photodetectors (SPPD) are becoming a promising candidate for application in high-sensitivity and high-speed SPPDs because they do not require batteries as an external power source. 21,22 For example, TiO 2 based self-powered photochemical UV detectors have been reported, but they are restricted to UV light. [23][24][25] To better use solar light for energy conversion, it is very important to extend the spectrum to the visible region.…”