1：Experimental Design and Method Selection:

The synthesis of α-Fe2O3 nanoparticles was carried out using a low-temperature simple solution process. The nanoparticles were characterized by XRD, SEM with EDS, TEM, UV-visible spectroscopy, and fluorescence spectroscopy.

2：Sample Selection and Data Sources:

The samples were prepared from ferric nitrate and diethylene triammine solutions, with potassium hexacyanoferrate (II) added, followed by NaOH to adjust pH.

3：List of Experimental Equipment and Materials:

Equipment included XRD (PANalytical X’Pert PRO), FESEM (JEOL-JSM-7600F), TEM (JEOL-JEM-2100F), UV-visible spectrophotometer (Carry-100, Bio UV-vis spectrophotometer), and fluorescence spectrophotometer (Perkin Elmer LS55). Materials included ferric nitrate, diethylene triammine, potassium hexacyanoferrate (II), NaOH, ethanol, methyl orange, and picric acid.

4：5). Materials included ferric nitrate, diethylene triammine, potassium hexacyanoferrate (II), NaOH, ethanol, methyl orange, and picric acid. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The synthesis involved mixing solutions under continuous stirring, refluxing, and annealing. Photocatalytic degradation of MO and fluorescence sensing of PA were performed under controlled conditions.

5：Data Analysis Methods:

The photocatalytic degradation was analyzed by measuring absorbance at 465 nm, and fluorescence quenching was analyzed using the Stern-Volmer equation.