NANOSIZED IMPLANTS OF Ag+, Cu+ AND Cu2+ IONS INTO THE SURFACE LAYER OF POLYCRYSTALLINE CdS PHOTOCATALYST FOR THE OXIDATION REACTION OF IODIDE IONS

Abstract

The process of construction of the nanosized photoactive systems based on cadmium sulfide has been developed. Additional ions Ag⁺, Cu⁺, Cu²⁺ can be implanted into the surface layer of CdS microcrystals leading to the formation of nanosized particles of corresponding sulfides. High redox photocatalytic efficiency was determined in the model reaction of potassium iodide oxidation for the low-doped samples of CdS containing silver and copper ions and the composite nanostructured CdS-based sulfides containing nanoparticles of Ag₂S, Cu₂Sі CuS. This effect is caused by the depression of electron-hole recombination because of reduction of the dope agent ions by free electrons, which results in the formation of reactive neutral atoms. Alternatively, this effect can also be caused by the transfer of photogenerated charges between likely charged clusters in nano- and microcomponents of the composite material.