1：Experimental Design and Method Selection:

Hydrothermal synthesis was used to construct the MOFs. Characterization methods included single crystal X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analysis, fluorescence spectroscopy, UV-Vis spectrophotometry, and X-ray powder diffraction.

2：Sample Selection and Data Sources:

Samples were synthesized from Eu(NO3)3·6H2O or Tb(NO3)3·6H2O, H3DMPhIDC, and H2DCB in water at 160°C for 72 hours. Cations for identification tests included Na+, K+, Mg2+, Ca2+, Co2+, Pb2+, Fe3+, etc.

3：List of Experimental Equipment and Materials:

Equipment included FLASH 1112 elemental analyzers, Nicolet NEXUS 470-FTIR infrared spectrometer, Netzsch STA 409PC differential thermal analyzer, Hitachi F-4600 fluorescence spectrometer, TU-1810 UV-VIS spectrophotometer, PANalytical X’pert PRO X-ray diffractometer, Bruker Smart APEXII CCD X-ray diffractometer. Materials included H3DMPhIDC, H2DCB, Eu(NO3)3·6H2O, Tb(NO3)3·6H2O, various cationic nitrates, and deionized water.

4：Experimental Procedures and Operational Workflow:

Synthesis involved heating mixtures in Teflon-lined autoclaves. Stability tests included immersion in water, boiling water, and pH solutions. Cation identification involved preparing suspensions with different cations and measuring fluorescence spectra. Quenching effects were studied by adding Fe(NO3)3 solutions incrementally.

5：Data Analysis Methods:

Data were analyzed using Stern-Volmer equation for quenching efficiency, with curve-fitting to determine KSV values. Structural data were refined using SHELXL program.