Interfacial Charge Transfer between Zinc Oxide Nanoparticles and Methyl Viologen: Influence of Size

Abstract

AbstractThe fundamental understanding of photoinduced electron transfer (PET) between semiconductor nanocrystals and dye molecules is very important to design efficient light harvesting system based on inorganic‐organic hybrid system. Here, we have investigated the photoluminescence quenching and charge transfer process from ZnO NPs to methyl viologen (MV2+) by using steady state and time resolved spectroscopy. Absorption spectroscopic studies reveal that the charge‐transfer (CT) complex is formed between ZnO NPs and MV2+ which gives distinct size dependent CT bands. The defect emission of ZnO NPs is found to be quenched significantly after adding MV2+ molecule. The charge transfer process between ZnO NPs and MV2+ is confirmed by using laser flash photolysis and the stability of CT complexes is found to be more prominent for 6.3 nm ZnO NPs with MV2+ than 4.2 nm ZnO NPs with MV2+. The study of the electronic interaction of ZnO NPs with MV2+ is very important for further applications in organic/inorganic hybrid optoelectronic materials.