Solvent-free synthesis of hierarchical Tb3+-doped Yttrium benzene-1,3,5-tricarboxylate metal organic framework nanosheets for fast and highly sensitive fluorescence detection of Fe3+ and Cr2O72− ions

Controllable synthesis of luminescent metal-organic frameworks (MOFs) having the merits of ease preparation, outstanding sensitivity and stability is of great significance for exploring their efficient sensing applications. Herein, we report a hierarchical terbium-doped yttrium-benzene-1,3,5-tricarboxylate MOF nanosheet via solvent-free synthetic strategy with a topological structure of MIL-78. The fluorescence property of the hierarchical Tb³⁺-doped Y-based MOF nanosheets can be tuned by adjusting the molar ratio of Tb³⁺ to Y³⁺ ions, and the Tb_0.5Y_0.5-MOF nanosheet-like morphology with the optimum characteristic Tb³⁺ ion green emission exhibited great potential acting as fluorescence probe for highly sensitive Fe³⁺ and Cr₂O₇²⁻ detection. The Tb³⁺-doped Y-MOF nanosheets show a fast response time of less than 1 s for Fe³⁺ ions. They also have low detection limits of 0.40 and 0.26 µM toward Fe³⁺ and Cr₂O₇²⁻ ions, respectively, as well as excellent stability. This work paves the way to explore intriguing hierarchical MOF-based luminescent materials for efficient fluorescence sensing applications.