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

Visible-light-responsive photocatalytic materials have important applications. In this article, through inserting electropositive ion Ba2+ into the three-dimensional framework of ZnSe, a one-dimensional chalcogenide Ba2ZnSe3 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 [ZnSe3]4- anionic straight chains parallel to the b direction, which are further separated by Ba2+ cations filling in the cavities. On the basis of the UV-vis-NIR diffuse reflectance spectroscopy, Ba2ZnSe3 possesses a typical direct band gap of 2.75 eV, which is in good agreement with the electronic structure calculation. Moreover, Ba2ZnSe3 shows good visible-light-responsive photocatalytic activity and excellent thermal stability and cyclability, which are favorable for its application.