Visible-Light-Responsive Chalcogenide Photocatalyst Ba₂ZnSe₃: Crystal and Electronic Structure, Thermal, Optical, and Photocatalytic Activity

Abstract

Visible-light-responsive photocatalytic materials have important applications. In this article, through inserting electropositive ion Ba 2+ into the three-dimensional framework of ZnSe, a one-dimensional chalcogenide Ba 2 ZnSe 3 has been obtained by traditional solid-state reaction. It crystallizes in orthorhombic centrosymmetric space group Pnma with unit cell parameters of a = 9.0744(2) Å, b = 4.4229(1) Å, c = 17.6308(4) Å, and Z = 4. Its structure features [ZnSe 3 ] 4– anionic straight chains parallel to the b direction, which are further separated by Ba 2+ cations filling in the cavities. On the basis of the UV–vis–NIR diffuse reflectance spectroscopy, Ba 2 ZnSe 3 possesses a typical direct band gap of 2.75 eV, which is in good agreement with the electronic structure calculation. Moreover, Ba 2 ZnSe 3 shows good visible-light-responsive photocatalytic activity and excellent thermal stability and cyclability, which are favorable for its application.