One-pot synthesis of CdS and Ni-doped CdS hollow spheres with enhanced photocatalytic activity and durability.

CdS and Ni-doped CdS hollow spheres were synthesized via a simple template-free one-pot method. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive spectroscopy analysis, X-ray photoelectron spectroscopy, and UV-vis absorption spectroscopy. The formation mechanism for the Ni-doped CdS hollow spheres was discussed. The prepared CdS and Ni-doped CdS hollow spheres showed the superior photocatalytic activity for the degradation of RhB under visible light (λ > 420 nm) irradiation, and 1.2 mol % Ni-doped CdS hollow spheres were found to be highly efficient for organic pollutants RhB and phenol removal. Moreover, this catalyst showed improved stability, and the activity did not decrease significantly after four recycles. The unique hollow spheres structure may favor the harvesting of exciting light due to multiple scattering within the interior space, and the doping of Ni(2+) may facilitate the generation of electrons and holes pairs and inhibit their recombination rate by act as a temporary trapping sites of photoinduced electrons.