Preparation and application of CsPbBr3 perovskite nanocrystal passivated by perfluoroglutaric acid

Abstract

The invention discloses preparation and application of a CsPbBr3 perovskite nanocrystal passivated by perfluoroglutaric acid. The preparation comprises the following steps: (1) preparing cesium perfluoroglutarate; (2) preparing a precursor solution; and (3) preparing the CsPbBr3 PNCs. Perfluoroglutaric acid is a bidentate ligand, the carbon chain length of the bidentate ligand is highly matched with lattice parameters of cubic phase CsPbBr3 PNCs, high binding energy is achieved through precise coordination of perfluoroglutaric acid to CsPbBr3 PNCs, and the product can still have good luminescence performance and excellent polar environment stability under simple passivation of a single acid ligand; and meanwhile, the PFGA-CsPbBr3 PNCs is exposed on the external C-F hydrophilic surface, so that the product shows good dispersity in various polar solvents. In addition, on the basis of the halogen exchange property of perovskite, a Cl <-> wavelength moving type fluorescent visual sensor is constructed by taking PFGA-CsPbBr3 PNCs as a fluorescent probe, and is used for homogeneous real-time efficient detection of chloride ions in urine and rapid identification of chloride ions in river and sea sand.

Description

technical field [0001] The invention belongs to the technical field of nanomaterials, in particular to a perfluoroglutaric acid passivation CsPbBr 3 Preparation and application of perovskite nanocrystals. Background technique [0002] In recent years, perovskite nanocrystals (PNCs) have been widely used in the field of fluorescence visualization sensing due to their excellent optical response and precisely tunable band gap width (for example, halogen exchange can cause wavelength shift in the fluorescence emission region of 360-700 nm). valued. However, the development is relatively slow. The main reason is that the inherent ionic properties of PNCs are highly sensitive to the environment, which makes their fluorescence properties easily quenched by the influence of air or polar solvents, and the detection of ions usually requires the diffusion of ions in a polar environment. Therefore, the preparation of polar dispersible and highly stable PNCs is of great significance fo...

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Problems solved by technology

However, due to the highly dynamic ion binding mode (i.e., the binding-dissociation process) at the interface between the ligand and PNCs, PNCs are prone to ligand shedding under the induction of polar solvents, which will lead to the stacking of PNCs particles and produce poor optical properties. bulk particles or polycrystalline

In addition, usually the carbon chain ends of the ligands on the surface of PNCs will form a non-polar interface, so in the purification process of PNCs, medium or weak polarity such as isopropanol or ethyl acetate is often used as a hydrophobic solvent to assist the precipitation of nanocrystals. But this bodes well for the unfavorable dispersion of conventional ligands in polar solvents

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