Nanostructured layered Sn3O4 for hydrogen production and dye degradation under sunlight

Abstract

Nanostructured layered Sn₃O₄ nanoplatelets were synthesized via a facile hydrothermal method. At low pH, the formation of SnO₂ was observed due to the existance of Sn(II). By tuning the pH of the hydrothermal reaction, Sn₃O₄ was conferred. The broadening of XRD peaks reveals the existance of nanocrystalline triclinic Sn₃O₄, which was also confirmed by Raman spectroscopy. Morphological examination displays the nanostructured layered plate-like structure with diameter of 20 nm and length of 100–150 nm. The optical band gap was observed to be 2.76 eV for Sn₃O₄. Considering the band gap was in the visible light region, investigations on the photocatalytic production of hydrogen and dye degradation were performed under sunlight. A maximum hydrogen evolution (3916 μmol h⁻¹/0.5 g) was obtained using the Sn₃O₄ nanoparticles, which is much higher than that found with SnO₂ (729 μmol h⁻¹/0.5 g) due to narrowing of the band gap. Hydrogen production from H₂S using Sn₃O₄ was reported for the first time. Sn₃O₄ also demonstrates excellent dye degradation activity. The high photocatalytic activity of Sn₃O₄ was attributed to its nanocrystalline nature and narrowing of the band gap.