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 H2O2assisted 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 mA cm-1 at a basis of 0 V and higher H2 generation rate with 1.43 x 104 mmol 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. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.