1：Experimental Design and Method Selection:

The vapor transport method was used with a horizontal tube furnace system to grow crystalline VO2 nanostructures on SiO2(300 nm)/Si and exfoliated graphene substrates. The method was chosen for its ability to produce crystalline nanostructures.

2：Sample Selection and Data Sources:

Si wafer pieces (1 cm x 1 cm or 2 cm x 2 cm) with a 300 nm SiO2 layer were used. Graphene nanosheets were exfoliated from high oriented pyrolytic graphite (HOPG) using 3M Scotch tape and transferred to the Si wafer. The number of graphene layers was confirmed by Raman spectroscopy.

3：List of Experimental Equipment and Materials:

Equipment included a horizontal tube furnace, alumina crucible, capacitance manometer (MKS Instruments, 626B11TQE), FE-SEM (FEI, Sirion), optical microscopy (Leica, DM500), Raman spectroscopy (Renishaw, inVia Qontor and NOST, FEX), TEM (JEOL, JEM-2100F HR), FIB (FEI, Helios NanoLab), and XPS (ThermoFisher Scientific, K-Alpha). Materials included vanadium(IV) oxide powder (V2O4,

4：9%, Sigma-Aldrich, No. 215821), high purity Ar gas (999%), acetone, ethyl alcohol, de-ionized water, and 3M Scotch tape. Experimental Procedures and Operational Workflow:

Substrates were cleaned ultrasonically in acetone, ethyl alcohol, and de-ionized water, then dried with nitrogen. Graphene was transferred to Si wafer. The source material (V2O4 powder) was vaporized at 1000°C in the furnace. Substrates were placed downstream at temperatures from 500°C to 800°C. The chamber base pressure was under 5 x 10^-2 Pa, purged with Ar gas. Carrier gas flow rate was 50-1000 sccm, and growth pressure was maintained at

5：4 kPa or 101 kPa using a gate valve. Growth duration was 5 hours. Morphology and crystallography were analyzed using FE-SEM, optical microscopy, Raman spectroscopy, TEM, and XPS. Data Analysis Methods:

Raman spectra were used to identify VO2 phases and graphene quality. TEM and FE-SEM images were analyzed for morphology and crystal structure. XPS peak fitting with Avantage software was used to analyze functional groups on substrates.