1：Experimental Design and Method Selection:

A hydrothermal method was used to synthesize BFO submicron cubes and 3D BFO/graphene composites. The effects of hydrothermal time, precursor pH, and GO concentration on crystallization and photocatalytic properties were investigated.

2：Sample Selection and Data Sources:

BFO was synthesized from Bi(NO3)3?5H2O and Fe(NO3)3?9H2O in a 1:1 molar ratio. GO was synthesized from natural graphite powder using a modified Hummer's method.

3：List of Experimental Equipment and Materials:

Chemicals from Aladdin, deionized water, NaOH solution, hydrogen peroxide, ascorbic acid, methylene blue dye. Equipment includes hydrothermal reactor, centrifuge, freeze-dryer, CHI660E electrochemical workstation, xenon lamp, SEM (S-4800, Hitachi), Raman spectroscope (Renishawin Via Raman Microscope), XRD (Siemens D5005), BET analyzer (Micromeritics ASAP 2020 M), UV-vis spectrometer (UV-2401PC, Shimadzu), TGA (PYRIS 1, PerkinElmer), TOC analyzer (Liquid Toc2, Elemenear).

4：Experimental Procedures and Operational Workflow:

BFO synthesis involved hydrothermal reaction at 200°C for 72 h with pH >

5：Composites were prepared by adding BFO to GO solutions with varying concentrations, reducing with ascorbic acid, and hydrothermal reaction at 160°C for 6 h. Photocatalytic tests used a three-electrode system with xenon lamp irradiation, measuring degradation of MB dye. Data Analysis Methods:

XRD and Raman for structural analysis, BET for surface area, UV-vis for band gap calculation using (αhν)^2 vs. hν plot, photocurrent measurements, and degradation rates from absorbance measurements.