Enhanced Photocatalytic Activity of ZnS:Mn2+ Quantum Dots

Abstract

The photocatalytic activity of Mn²⁺ doped ZnS quantum dots stabilized by glutathione capping agent in aqueous media was studied in situ by photoluminescence spectroscopy. The methylene blue was chosen as model organic dye for photodecomposition under excitation in near UV-range. It is shown that the rate of photodegradation of the methylene blue depends strictly on the concentration of the manganese activator ions and the presence of its own intrinsic defects in the host ZnS crystal lattice. It is found that the most effective photocatalyst are ZnS quantum dots doped with 0.25 at % of Mn²⁺ providing the total dye decolorization within 5 minutes.