Rare metal doping of the hexahydroxy strontium stannate with enhanced photocatalytic performance for organic pollutants

Rare metal (La or Nd) doped hexahydroxy strontium stannate with different dopant contents was synthesized via a facile hydrothermal route. The rare metal doped samples were investigated by X-ray diffraction (XRD), electron microscopy, solid diffuse reflectance spectrum, X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) spectroscopy. The morphology of the doped samples is closely relative to the rare metal dopant content transferring from the nanorods to nanoflakes and nanoscale particles for La and Nd doping, respectively. 2wt.% rare metal doped hexahydroxy strontium stannate possesses the smallest band gap value with 3.26 eV (La doping) and 3.25 eV (Nd doping) which enhances the charge carriers transfer efficiency. The rare metal doped hexahydroxy strontium stannate shows enhanced photocatalytic performance for the crystal violet degradation under ultra-violet (UV) light irradiation. 2wt.% rare metal doped hexahydroxy strontium stannate has the best photocatalytic activity for the removal of crystal violet under UV light irradiation for 120 min. The rare metal doped hexahydroxy strontium stannate possesses high stability, and is reusable for the crystal violet degradation.