Research group of Liang Changhao, Institute of solid state, Chinese Academy of Sciences, has made progress in in-situ dynamic spectral monitoring of selenium colloidal phase transition

Recently, Liang Changhao, a researcher in the laboratory of nanomaterials and nanostructures, Institute of solid physics, Chinese Academy of Sciences, based on the self built "in-situ dynamic spectrum analysis platform for metastable nanoparticles in liquid phase", made progress in the in-situ dynamic spectrum monitoring of the growth and phase change of selenium (SE) nanomaterials in different solvents, and relevant research results were published in applied surface Science （ Appl Surf Sci 2019 , 466 , 1000-1006 ）。 The key to understand the formation mechanism of nanocrystals is to realize the dynamic monitoring and analysis of the intrinsic growth process of metastable nanoparticles, which is an important technical support for the accurate preparation and physical property control of nanostructures at the atomic and molecular levels Despite the existing liquid in situ TEM and in situ x Because of its high spatial resolution, X-ray diffraction and other technologies provide an important research method for exploring the nucleation and growth mechanism of nanomaterials in liquid-phase system, but there are still some limitations, such as low time resolution, limited number of in-situ monitoring samples, etc.; in addition, high-energy electron beam or X-ray For metastable nanoparticles, X-ray is an external energy source, which will interfere with the intrinsic growth of nanocrystals and affect in-situ dynamic monitoring and analysis Based on this, Liang Changhao's research group built the "in-situ dynamic spectrum analysis platform of metastable nanoparticles in liquid phase" through independent design, which is used to reveal the change rule of the size, structure and physical properties of metastable nanoparticles, and provide scientific basis and key technical support for the precise control of the growth and metastable phase capture of laser ablation technology in liquid phase Taking se colloid as an example, in order to avoid the interference of surfactants and reactive residual ions on the growth of nanocrystals, the researchers of the research group first used the liquid-phase laser ablation technology to melt the se target in deionized water, and obtained the red amorphous a-Se nano colloid solution The se nanoparticles were then centrifuged and dispersed into three different polar aprotic solvents DMF, CP and EAC for aging Using in-situ Raman spectroscopy of the liquid phase in the platform, the researchers found that with the aging process, a-Se in the three solvents decreased gradually, and t-se increased gradually By analyzing and simulating the relationship between t-se Raman peak intensity and aging time, the researchers observed that the phase transition rate of Se in different solvents was different In the three solvents, the transformation rate of se is DMF > CP > EAC The results show that in different solvents, the growth rate of phase transition from a-Se to t-se is a power function of time, and has a positive correlation with the polarity of solvent molecules This work was supported by the national key basic research and development plan of the Ministry of science and Technology (973 project), the equipment development project of the Chinese Academy of Sciences and the National Natural Science Foundation of China.