1：Experimental Design and Method Selection:

A modified green sol-gel method using Aloe Vera gel as a natural template was employed to synthesize pure and Mg-doped nickel ferrite nanoparticles. This method was chosen for its eco-friendliness, cost-effectiveness, and ability to produce ultrafine particles with narrow size distribution.

2：Sample Selection and Data Sources:

Stoichiometric quantities of nickel nitrate and ferric nitrate were used with molar ratios of M3+/M2+ of 2:1, dissolved in double distilled water. Aloe Vera extract was added, followed by Mg dopant as nitrate salt. Samples were calcined at 350°C for 1 hour.

3：List of Experimental Equipment and Materials:

Chemicals from Merck (≥98%), IC dye and Phenol from S. D. Fine chemicals, Aloe Vera leaves, de-ionized water, aq. Ammonia (25%), autoclave, magnetic stirrer, centrifuge, Millipore filter (

4：45 μm). Characterization equipment:

TECNAIF T-30 HRTEM, Hitachi-3000 SEM, Perkin Elmer FTIR Spectrum1000 spectrometer, SL 159 ELICO UV-Visible spectrophotometer, Shimadzu Powder X-ray diffractometer, Horiba Flurolog Spectrofluorometer.

5：Experimental Procedures and Operational Workflow:

Mixing of precursors with Aloe Vera extract, stirring at 80°C to form gel, pH adjustment to 6 with aq. Ammonia, drying in autoclave at 200°C, calcination at 350°C. For photocatalytic tests, 40 mg catalyst dispersed in 250 ml of 20 ppm pollutant solution, stirred under sunlight, samples taken at intervals, centrifuged, filtered, and analyzed by UV-Vis spectrophotometry.

6：Data Analysis Methods:

XRD for crystal structure using Debye-Scherrer formula, UV-Vis for band gap calculation using Tauc plot, PL for emission spectra, EIS for charge transfer resistance, and kinetic analysis for photocatalytic degradation rates.