## 3 Results  
### Silica Nanoflakes Characterization  
The morphology of the obtained materials was studied with transmission electron microscopy and scanning electron microscopy. Figure 1A presents graphene oxide and Figure 1B,C reveals the morphology of obtained silica flakes after GO removal. LDH Mg/Al and the formed silica flakes on them are presented in Figure 1D-F, respectively. The porous structure of silica flakes obtained on both templates is clearly visible. In the flakes obtained on LDH Mg/Al, a mesoporous shell was also deposited on the edges (see Figure 1F). In the case of flakes obtained on graphene oxide, it can be assumed that the deposition took place only on the planes of graphene oxide. Elemental analysis of silica flakes and templates were carried out using X-ray dispersion spectroscopy as the TEM mode. Supplementary Materials Figure S1 shows an EDX analysis of templates and silica flakes after removal of the templates. Elemental analysis of graphene oxide confirmed that the sample consists of carbon and oxygen. In an EDX spectrum of LDH Mg/Al, there are signals from oxygen, aluminum, and magnesium. For both samples, the analysis showed that they consist of oxygen and silicon elements. The analysis confirms that the templates were effectively removed from the silica flakes. All the samples have copper signals that originate from the TEM grids. The thickness and size distribution of the nanostructures were estimated using atomic force microscopy. Basing on analysis of the AFM images (Figure 2), it was determined that the size of the flakes formed on the graphene oxide template is in the range of 40-220 nm, with the peak in the range of 80-100 nm. The flakes fabricated on the LDH Mg/Al were in the range of 200-1000 nm with the peak in the range of 400-500 nm. The obtained materials differed in thickness as well. The flakes obtained on the LDH Mg/Al template were larger and thicker than those obtained on graphene oxide. Flakes of mSiO\({}_{2}\) after GO thickness were \(\approx\)4 nm, while those of mSiO\({}_{2}\) after LDH Mg/Al were \(\approx\)6.5 nm. Figure 1: Transmission electron microscopy image of graphene oxide (GO) (**A**) and silica flakes obtained on GO (**B**,**C**); double-layered magnesium and aluminum hydroxide LDH (**D**) and obtained on LDH Mg/Al (**E**,**F**). Figure S2 presents XRD patterns of GO, mSiO\({}_{2}\) after GO, LDH Mg/Al, and mSiO\({}_{2}\) after LDH Mg/Al. The GO and LDH Mg/Al pattern exhibits strong, characteristic peaks corresponding to the (002) plane of GO and (003), (006), and (009) planes of LDH [28]. After purification, silica flakes show the broad peak at 22\({}^{\circ}\) indicating that the flakes are composed only from amorphous silica. The detailed pattern analysis and XRD patterns are presented in the supporting information. Raman analysis presented in the supporting information (images A and B in Figure S3) proved that the pristine template was GO and LDH Mg/Al, and after purification, obtained flakes are composed of silica. The surface area, pore volume, and diameter distribution of the mesoporous silica flakes (mSiO\({}_{2}\)) from both templates (Table 1) were calculated using the Brunauer, Emmett, and Teller (BET) method (isotherms and pore diameter distribution are presented in the supporting information). Figure S4A presents N\({}_{2}\) adsorption/desorption isotherms and the pore size distribution of both samples. From the multipoint BET isotherm, total surface areas were calculated to be 738 m\({}^{2}\)/g and 839 m\({}^{2}\)/g for mSiO\({}_{2}\) after GO and mSiO\({}_{2}\) after LDH Mg/Al, respectively. The isotherms, identified as type IV according to the International Union of Pure and Applied Chemistry (IUPAC) classification, are typical for mesoporous materials [29].