An excellent H2 production photoelectrode based on mixed valence Sn3O4 nanoflake arrays treated by H2O2 hydrothermal reaction

To design nanostructured photoelectrodes with unique morphology and suitable band structure is a crucial step for potential photoelectrochemical application. For above purpose, the compact Sn₃O₄ nanoflakes with the smooth surface have been directly grown on carbon paper substrate by a simple hydrothermal method. It is found that the molar ratio of Sn²⁺ and Sn⁴⁺ ions in Sn₃O₄ nanoflakes can be modulated by the subsequent H₂O₂-assisted hydrothermal treatment. The effect of different molar ratio on the energy band has been investigated systematically, together with the evolution of the surface morphology of nanoflakes. Finally, a highly efficient photoelectrode based on Sn₃O₄ nanoflake has been prepared by the H₂O₂-assisted hydrothermal process, which is of larger active surface area and suitable band structure, and therefore exhibits the excellent photocurrent response and photocatalytic performance for H₂ production. The photoelectrode based on Sn₃O₄ nanoflake displays enhanced photocurrent with 40 μA cm^?1 at a basis of 0 V and higher H₂ generation rate with 1.43 × 10⁴ μmol h^?1 g^?1, much better than those of the original sample. Such superior performance can be probably attributed to the combined effect of unique porous nanoflake-structured, higher active surface area and suitable band structure.