Abstract: Organic-inorganic hybrid luminescent materials are highly favored in the luminescence anti-counterfeiting field due to their tunable structural and luminescent properties. This study investigates Sb(III) doped Bi(III)-based zero-dimensional organic-inorganic hybrid metal halides, demonstrating the transformation from kinetic products (compound 1) to thermodynamic products (compound 2) by various crystal growth methods. X-ray powder diffraction and fluorescence spectroscopy were employed to characterize their phase and optical properties, revealing distinct differences between the two compounds. Compound 2 exhibits fluorescence quenching when exposed to distilled water and possesses robust hydrophobic properties, allowing for stable long-term storage in aqueous environments. Leveraging the exceptional color-changing properties of compound 2, a simple water-writable fluorescent anti-counterfeiting board/paper was fabricated. This experiment exemplifies the principle that “structure determines properties” and embodies the educational philosophy of “learning through application”. The experimental design and implementation aim to cultivate students' innovative thinking and enhance their abilities to analyze and solve practical issues.

Key words: Sb(III) doped Bi(III)-based hybrid halides, Photoluminescence, Kinetic and thermodynamic conversion, Water-induced chromism, Writable fluorescent anti-counterfeiting application