1：Experimental Design and Method Selection:

The study involved preparing aluminum-doped metal ferrites via co-precipitation method, followed by characterization using XRD, SEM, EPR, BET, and photocatalytic evaluation under UV irradiation.

2：Sample Selection and Data Sources:

Samples included various metal ferrites (Zn, Cu, Cd, Co, Ni, Cr) doped with Al at concentrations of

3：005 to 013 mol-1, prepared from analytical grade reagents. List of Experimental Equipment and Materials:

Equipment included Rigaku X-ray diffractometer, JEOL JSM-7600F SEM, Quantachrome ASiQ automated gas adsorption system, Bruker EMX-500 EPR spectrometer, UV-Vis spectrophotometer (Thermo Fisher Scientific Evolution 300), and Philips 8W UV lamp. Materials included metal nitrates, NaOH, malachite green dye, and distilled water.

4：Experimental Procedures and Operational Workflow:

Ferrites were prepared by dissolving metal nitrates, adding NaOH dropwise at pH 7 and 60-70°C, stirring, washing, drying at 100°C, grinding, and calcining at 650°C. Photocatalytic tests involved adding ferrite samples to MG dye solution, stirring in dark, irradiating with UV lamp, sampling at intervals, filtering, and measuring absorbance.

5：Data Analysis Methods:

Data were analyzed using XRD for crystallinity, SEM for morphology, EPR for magnetic properties, BET for surface area, and kinetic analysis (pseudo-first order) for photocatalytic degradation rates.