1：Experimental Design and Method Selection:

The study employed a photo-Fenton reaction system using β-Fe2O3 as a catalyst under visible light irradiation to degrade organic dyes and phenol. The rationale was to leverage the visible light absorption and catalytic properties of β-Fe2O3 for efficient hydroxyl radical generation.

2：Sample Selection and Data Sources:

Organic contaminants included rhodamine B (RhB), methyl orange (MO), alizarin red (AR), and phenol, with concentrations specified (e.g., 20 mg/L for dyes, 3 mg/L for phenol). Catalysts were synthesized in-house, and solutions were prepared using deionized water.

3：List of Experimental Equipment and Materials:

Equipment included a photoreactor with a 300 W Xenon lamp (light source, λ > 420 nm), Rigaku Ultima III X-ray diffractometer for XRD, HITACHI S3400 N II SEM for morphology, Micromeritics ASAP 2020 for BET surface area analysis, NEXUS870 FT-IR spectrometer, VARIAN CARY Eclipse fluorescence spectrometer for PL, Horiba Scientific Fluorescence-3 spectrometer for TR-PL, ULVAC-PHI PHI 5000 Versa Probe XPS, Shimadzu UV-2550 UV-vis spectrophotometer, Shimadzu TOC-L analyzer for TOC, Hitachi 180-80 AAS for iron content, and Waters SQD2 LC-MS with Agilent DB-17MS column for intermediate analysis. Materials included Fe2(SO4)3, Na2SO4, NaCl, H2O2, dyes, phenol, and tertiary butanol.

4：Experimental Procedures and Operational Workflow:

Synthesis of β-Fe2O3 involved dissolving Fe2(SO4)3 and Na2SO4, evaporation, ball milling with NaCl, calcination at 450°C, and washing. Photo-Fenton experiments involved stirring catalyst, contaminant solution, and H2O2 to achieve adsorption-desorption equilibrium, irradiating with visible light, sampling at intervals, and analyzing degradation efficiency. For phenol degradation, LC-MS was used to identify intermediates, and toxicity was assessed using E. coli growth tests.

5：Data Analysis Methods:

Degradation efficiency was calculated as [(C0 - C)/C0] × 100%, kinetic rate constants were determined using pseudo-first-order kinetics, hydroxyl radical production was verified using terephthalic acid and PL spectroscopy, and intermediates were identified via LC-MS mass spectrometry.