Influence of Si quantum dots on water molecules icing

The structure of liquid water is strongly influenced by Si quantum dots (Si QDs). We employed Raman spectroscopy to investigate how Si QDs affect the icing point of water. In contrast with the Raman spectra of pure water, Raman spectra of Si QDs water solutions exhibit some distinct characteristic features. The Raman spectra present that liquid- ice Ih phase transition takes place at 264 and 266 K in 5 and 2 nm Si QDs solutions respectively, which is higher than that of pure water (257 K). These phenomena are contributed to the electric field generated by Si QDs and the hydrogen bonds formed between silanol groups and water molecules. The results can open the way to understand the interaction between water molecules and quantum dots in some environments.