## 3 Results  
### Characterization of Ag\({}_{7}\)No\({}_{11}\):SiO\({}_{2}\)  
Synthesis of higher oxidation states of metals, such as silver oxynitrate, may proceed through the addition of a soluble metal to a strong oxidizing agent [30]. Aqueous oxidization of silver nitrate by potassium persulfate, as per Equation (3), results in the formation or deposition of Ag\({}_{7}\)NO\({}_{11}\). \[ \begin{array}{c}7\mathrm{AgNO_{3\;(aq)}+K_{2}S_{2}O_{8\;(aq)}+8H_{2}O_{(l)} \to}\\ \mathrm{Ag_{7}O_{8}NO_{3\;(s)}+6 HNO_{3\;(aq)}+H_{2}SO_{4\;(aq)}+K_{2}SO_{4\;( aq)}+4H_{2\;(g)}}\end{array}  \tag{3}\]  
Based on the methods described herein, a series of silver oxynitrate-silica co-deposition products were prepared through the addition of an alkaline potassium silicate (K\({}_{2}\)SiO\({}_{3}\)) to a potassium persulfate solution prior to silver nitrate addition. Within the series of co-deposition products, the molar equivalents of silicon dioxide to silver were incrementally augmented following the series: 0:1, 0.1:1, 0.25:1, and 0.5:1 molar equivalents SiO\({}_{2}\):Ag; these co-deposition products are herein referred to as Ag\({}_{7}\)NO\({}_{11}\):SiO\({}_{2}\). Subsequent to their isolation, the relative solid-state composition of the powders was determined by X-ray diffractometry (XRD). Principal diffraction patterns collected from each the powders, shown in Figure 1, were in agreement with the crystallographic parameters for Ag\({}_{7}\)NO\({}_{11}\)[29]. Minor diffraction patterns were identified in each of the powder samples in agreement with the crystallographic parameters for silver sulfate. No additional diffraction patterns were identified in any of the powder samples. Silica gels formed from alkali silicates are commonly amorphous and poorly crystalline and therefore are expected to have limited or indiscernible diffraction patterns [31]. The relative diffraction peak area for silver sulfate Ag\({}_{2}\)SO\({}_{4}\) (28.1 \({}^{\circ}\)2\(\Theta\)) versus silver oxynitrate (36.3 \({}^{\circ}\)2\(\Theta\)) was identified to increase with the relative molar ratio of SiO\({}_{2}\):Ag, as shown in Figure S1. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to observe the structural composition and distribution of silver oxynitrate and silica within the isolated products. SEM images of silver oxynitrate control and Ag\({}_{2}\)NO\({}_{11}\):SiO\({}_{2}\) prepared at different silica concentrations ranging from 0:1 to 0.5:1 molar equivalents SiO\({}_{2}\):Ag are shown in Figure 2. It is observed from these images that distinct cuboctahedron structure of silver oxynitrate is conserved from 0:1 to 0.25:1 SiO\({}_{2}\):Ag, where the silica is observed as amorphous structures. At 0.5:1, SiO\({}_{2}\):Ag solid silica gel is the primary structure observed and the geometric silver oxynitrate structures are not visibly detected. Upon increasing the relative concentration of silica, it is also observed that the relative crystalline size of the silver oxynitrate decreases from 0:1 to 0.5:1 SiO\({}_{2}\):Ag. This reduction in crystalline size upon increasing silica concentration was also corroborated by XRD, employing the Debye-Scherrer equation, as shown in Figure S2 [32]. Complimentary to the SEM images, TEM provides a spatial orientation of the silver within the silica framework as the density disparity between silver oxynitrate and silica affords clear demarcation between the materials as shown in Figure 3. At a low relative concentration of silica, 0.1:1, molar equivalents SiO\({}_{2}\):Ag, the distinct cuboctahedra structure of silver oxynitrate is observed as a black silhouette, Figure 3A-C. Surrounding silver oxynitrate, the less electron dense structure of silica is observed on the structural faces of silver oxynitrate, Figure 3B, and encasing the silver oxynitrate particles in a framework of silica gel, Figure 3A.