Degradation of Rhodamine B Under Visible-Light by Cu-Doped ZnAl Layered Double Hydroxide

The Cu-doped ZnAl layered double hydroxides (LDH) were papered by coprecipitation. The prepared samples were characterized by mutiple techniques including X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse-reflectance spectroscopy (UV-vis DRS). The doping of Cu²⁺ into the LDH sheets results in formation of the distorted CuO6 octahedrons which contribute for the excitation of electrons under visible light. The doped Cu²⁺ also serves as photo-generated charges separator and improves the visible-light-driven photocatalytic activity of ZnAl LDH. A degradation mechanism based on the hydroxyl radical as the active species was proposed.