1：Experimental Design and Method Selection:

The study employed a CTAB assisted hydrothermal method for the synthesis of CNPs modified ZnO nanoflakes. The methodology included the fabrication of defects enrich ZnO nanoflakes and their modification through different densities of CNPs.

2：Sample Selection and Data Sources:

The samples included pure ZnO nanoflakes and ZnO nanoflakes functionalized with different loading of CNPs (0.3 mM, 0.6 mM and 0.9 mM).

3：3 mM, 6 mM and 9 mM). List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Field-emission scanning electron microscopy (ZESIS), transmission electron microscopy (JEOL-2100F, Japan), and scanning electron microscopy (ZESIS, EVO) were used for compositional and morphological analysis. XRD results were acquired by using Cu Kα source (Rigaku, ultima). Raman studies were performed through Raman spectrometer (Renishaw inVia). UV-DRS and photoluminescence spectra were recorded from the dual-beam spectrophotometer (Shimadzu UV-2450) and Shimadzu (RF-600) spectrometer system.

4：Experimental Procedures and Operational Workflow:

The synthesis process involved mixing Zn(NO3)2·6H2O into a solution of CTAB under continuous stirring, followed by the addition of NaOH solution. The obtained solution was transferred into a Teflon chamber and sealed with the stainless steel chamber, then placed into an electric oven. The powder was collected, washed, and dried.

5：Data Analysis Methods:

The optical nature of ZnO nanoflakes and modulation in their optical properties with the functionalization with CNPs were analyzed through the UV-DRS technique. The bandgap evaluation of each sample was carried out by Tauc plots.