Background and overview[2]
Hydrated yttrium phosphate is yttrium phosphate with the crystal structure of the mineral churchite. Rare earth phosphates have good chemical stability and thermal stability, and have the advantages of large refractive index and low phonon energy. They are widely used as the matrix of luminescent materials. In these rare earth phosphates, the electrons in the 4f orbital of the yttrium ion are in a completely empty state, and no f-f transition will occur. Therefore, there will be no non-radiative transition and additional energy consumption. Therefore, yttrium phosphate is often used as the first choice material for luminescent substrates. , is also one of the current hot spots in the field of rare earth material chemistry.
Related research[1]
Transition metal oxides have rich physical and chemical properties due to their diverse valence electron structures, and show broad application prospects in the fields of optics, magnetism, catalysis, and batteries. By effectively synthesizing transition metal oxide nanomaterials and exploring their synthesis mechanism, we can effectively control the size, chemical composition and physical properties of the target nanostructure, which plays an important role in further exploring the relationship between structure and physical properties. Through a series of chemical means, the “bottom-up” integration of nanocrystals, that is, the assembly into functional bodies with higher-level structures, is of great significance to the realization of designing and synthesizing functional materials according to people’s wishes. Huo Ziyang of Tsinghua University has conducted systematic exploration and research on the design, synthesis mechanism, functional assembly and physical properties of new methods for the synthesis of transition metal oxide nanostructures.
Based on the mechanism of phase transfer and phase separation, hydrated yttrium phosphate nanocrystals with uniform sizes were successfully prepared; the morphology and size of the nanocrystals were controlled, and the mechanism of nanocrystal formation and morphology evolution was discussed, enriching and developed methods for the synthesis of rare earth nanostructures. By utilizing the interaction generated by the overlapping of long organic chains on the surface of nanocrystals, the two-dimensional assembly of nanocrystals is achieved, laying an experimental foundation for the assembly from nanocrystals to advanced superstructures.
Based on the stable icosahedral structure of cerium ammonium nitrate and its precursor, a method for large-scale synthesis of 3nm cerium oxide nanocrystals in liquid phase was developed, and its catalytic performance after loading gold was studied; by increasing the reaction in the system Colloidal nanoparticles with ordered superstructure were directly prepared by adjusting the concentration of the substance. The three-dimensional assembly behavior of the nanocrystals during the synthesis process was observed, which provided experimental basis for exploring the formation and application of colloidal particles with ordered superstructure. A square rubber additive method for liquid-phase synthesis of titanium dioxide nanocrystals with different morphologies was designed; the nanocrystals were assembled by using normal-phase micelles formed by a water-oil system, and their catalytic and battery properties were studied. Designed a composite bilayer of organic molecules and inorganic substances based on a layered structure, and developed a universal method for synthesizing ultra-fine (below 2 nm) transition metals and their oxidation nanostructures; in terms of experimental methods, nanocrystals were realized The combination of synthesis and assembly successfully constructed functional assemblies with promising applications.
