Green and facile synthesis of high-quality water-soluble Ag-In-S/ZnS core/shell quantum dots with obvious bandgap and sub-bandgap excitations

High-quality water-soluble Ag-In-S/ZnS core/shell quantum dots have been successfully synthesized via a facile and green method, with mercaptosuccinic acid and sodium citrate as dual ligands in one pot. The fabricated quantum dots exhibit excellent optical characteristics, including photoluminescence quantum yield (PLQY) of up to 50%, and the obvious first excition absorption peak. The emission peak of Ag-In-S/ZnS core/shell quantum dots can be tuned from 507 to 580 nm which covers the most of the visible light . Finally, the as-prepared Ag-In-S core quantum dots can be used directly in ion probe , achieved the direct visual inspection of Pb 2+ .