Tailoring the optical, magnetic, and photocatalytic properties of ZnS quantum dots by rare-earth ion doping

Abstract Gd-doped ZnS quantum dots (QDs) were synthesized through a hydrothermal route. The energy gap of ZnS QDs could be tuned as a function of the Gd doping concentration. The room-temperature electron paramagnetic resonance spectra of the Gd-doped ZnS QDs showed two resonance signals at g ≈ 2.052 and 2.813, which were attributed to the Gd (III) ions located at sites with weak and intermediate crystal fields, respectively. In addition, the as-synthesized Zn0.49Gd0.01S and Zn0.47Gd0.03S QDs displayed well-defined room-temperature ferromagnetism. The photocatalytic degradation rates of all the fabricated samples were assessed on the phenol red dye under the UV light illuminations.