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

Abstract

To improve the effective separation of the photogenerated electrons and holes, SnO x @β-SnO composites on titanium meshes were prepared by using a standard one-step hydrothermal procedure. As photoanodes in photoelectrochemical cell, the SnO x @β-SnO composites exhibited a photocurrent density of 150 μA cm −2 at 0.0 V versus Ag/AgCl under visible light illumination. The improved photocurrent can be explained as, the Sn 2+ 5s impurity states in SnO 2 have a band gap energy of 2.24 eV, SnO x @β-SnO composites construct a type-II heterojunction. And titanium meshes have a good conductivity, which is beneficial to transferring electron from the conduction band of SnO 2 to external circuit. Furthermore, the SnO x @β-SnO heterostructures have a larger electrochemical specific surface area, and stronger light absorption from 350-800 nm.