1：Experimental Design and Method Selection:

The study involved synthesizing Fe3O4 and Cu-functionalized SiNWs using in situ and infiltration methods to create a heterogeneous catalyst for phenol degradation. The rationale was to enhance catalytic properties and enable magnetic recovery.

2：Sample Selection and Data Sources:

Silicon powder (

3：9% < 500 mesh) and other chemicals were used as starting materials. Phenol solutions were prepared for degradation tests. List of Experimental Equipment and Materials:

Equipment included Teflon autoclave, magnetic stirrer, oven, SEM (AIS2100, Seron Technology), TEM (Zeiss-LEO906), XRD (Bruker AXS D8 Advance), BET sorptometer (Micromeritics ASAP 2010), spectrophotometer (Shimadzu MPC-2200), UV spectrophotometer (MAPADA 3200UV), HPLC (Agilent 1200), TOC analyzer (Shimadzu TOC-5050A), and pH meter. Materials included FeCl3, AgNO3, Cu(NO3)2, ethylene glycol, HF, H2O2, HNO3, acetone, ethanol, NaHCO3, Na2SO4, NaOH, HCl, NH4OH, 4-aminoantipyrine, potassium ferricyanide, and NaNO

4：Experimental Procedures and Operational Workflow:

SiNWs were fabricated via metal-assisted chemical etching with Ag and HF/H2O

5：Fe3O4 nanoparticles were synthesized solvothermally. The catalyst was prepared by mixing SiNWs with Fe3O4 and Cu salts using in situ and infiltration methods, followed by drying. Phenol degradation experiments involved adding catalyst to phenol solution with buffers, stirring, and measuring degradation via UV and HPLC. Data Analysis Methods:

Data were analyzed using UV spectrophotometry at 500 nm, HPLC for qualitative evaluation, TOC analysis, and BET for surface area and porosity. Statistical methods included the Rietveld refinement for crystallite size calculation.