1：Experimental Design and Method Selection:

A two-step synthesis involving thermal decomposition and hydrothermal methods to create nanocomposites with varying NiFe2O4 weight fractions (10%, 20%, 30%). Characterization techniques include XRD, FE-SEM, EDS, XPS, PL, VSM, and DRS to analyze structure, morphology, and properties. Photocatalytic activity evaluated by degrading crystal violet dye under visible light.

2：Sample Selection and Data Sources:

Samples include pure NiFe2O4, Bi24O31Br10, and their composites. Dye solution (crystal violet, 10 mg/L) used for degradation tests.

3：List of Experimental Equipment and Materials:

Materials include bismuth nitrate, iron chloride hexahydrate, ethylene glycol, nickel chloride hexahydrate, sodium hydroxide, crystal violet, potassium bromide. Equipment includes autoclave, XRD (D/max-2500, Rigaku), FE-SEM (SUAPR55, Zeiss), EDS, XPS (ESCALAB 250Xi, Thermo Fisher Scientific), PL spectrophotometer (FLs980, Edinburgh), VSM (LakeShore 7404), UV-vis spectrophotometer (UV-2450, Shimadzu), FTIR spectrometer (Nicolet iS50, Thermo Fisher Scientific), Xe arc lamp with cut-off filter.

4：Experimental Procedures and Operational Workflow:

Synthesis of Bi24O31Br10 via hydrothermal method at 140°C for 12 h, followed by calcination. Synthesis of composites by mixing solutions, adjusting pH, and hydrothermal reaction at 180°C for 24 h. Photocatalytic tests involve stirring dye with catalyst in dark for 30 min, then irradiating with visible light, sampling every 20 min, and measuring concentration with UV-vis spectroscopy.

5：Data Analysis Methods:

Degradation percentage calculated using concentration changes. Rate constants derived from linear plots of -ln(Ct/C0) vs. time. Active species identified using scavengers (EDTA-2Na for h+, BQ for ?O2-, IPA for ?OH).