## 3 Results and Discussion
### Powder X-ray Diffraction  
X-ray Diffraction (XRD) was used to analyze the phase composition and crystal structure of the prepared materials. Figure 5a shows the XRD pattern of the sample CSHDS. The XRD pattern of CSHDS is typical of layered materials, showing sharp symmetric reflections at a low angle with interlayered spacing (0.78 nm) and weak asymmetric reflections at high angles with interlayered spacing (0.39 nm and 0.268 nm). The good agreement between these values corresponding to successive diffractions by planes, i.e., 0.78 nm = 2 \(\times\) 0.39 nm = 3 \(\times\) 0.268 nm, reveals nanolayered structures with highly packed stacks of HDS layers. Although there are no XRD results reported in the literature for cobalt-tin-cyanate HDS, these diffraction peaks are in agreement with the cobalt nickel  
Figure 4: SEM images of CSLDH-2 at different locations. carbonate hydroxide hydrate phase found using JCPDS card number 40-216. For nanoxygen hydroxyl double salt structures, the main peaks observed at 0.78 nm, 0.39 nm, and 0.268 nm, which are agreement with the diffraction of the basal planes--(003), (006), and (009), respectively. In addition, the non-basal reflection at 0.299 nm was considered to be relative to the (100) plane. The value for the (003) peak at 0.78 nm is slightly larger than the value reported for cobalt nickel hydroxyl double salt, whose value is 0.76 nm in the case of the carbonate anion as the guest and the cobalt combined with nickel [20; 27]. This value depends on the size of the anion. This shift from 0.76 nm to 0.78 nm suggests the presence of cyanate or nitrate anions instead of carbonate in addition to the incorporation of tin instead of nickel in the lattice of hydroxyl double salts [28; 29]. By changing tin from a divalent element to tetravalent element, different kind of layered structures were observed, as shown in Figure 5b. The XRD pattern of the sample CSLDH-1 showed three peaks at spacing 0.794 nm, 0.393 nm, and 0.269 nm. This pattern showed strong and sharp peaks at low 2\(\Theta\) and weak peaks at high 2\(\Theta\), indicating some common features of the layered structures. For layered double hydroxides (LDHs), hydrotalcitelike materials, the reflections of the main planes (003), (006), and (009) agree with the observed peaks at spacing 0.794 nm, 0.393 nm, and 0.269 nm, respectively. However, the value of the reflection of the main plane (003) which was observed at 0.79 nm, is significantly larger than the value reported for natural hydrolcite, whose value is 0.76 nm in the case of the carbonate anion as the guest [30; 31]. This value depends on the size and the orientation of the anion in addition to the thickness of the bructelike layers (0.48 nm for hydrolcite). This means that the interlayered spacing is not compatible with the size of carbonate anion suggesting presence of cyanate or nitrate anions. In case of the sample CSLDH-2, the main peaks of the layered structure became opaque. Figure 5c shows that CSLDH-2 has a non-crystalline structure because of the high content of tetravalent tin, leading to presence of high positive charges inside the nanolayers of the LDHs. It means that the high positive charges caused high concentrations of anions among the nanolayers, leading to high distortion and more curvature for the nanolayers of LDHs. Therefore, the peaks of the XRD became opaque and the nanofibers became clearer in SEM images, which was discussed above. However, the weak peak observed at spacing 0.798 nm indicates presence of layered double hydroxide in a distortion state. Figure 5: X-ray diffraction of **(a)** CSHDS, **(b)** CSLDH-1, and **(c)** CSLDH-2. According to the SEM images and X-ray results, the transformation of nanolayered materials to nanofibers can be explained through schematic representation in Figure 6. From the known layer thickness, 0.48 nm, and the size of cyanate anion, 0.34 nm, the interlayer spacing available for the anion was calculated as 0.31 nm.