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Ag2O is trigonal omega structured and crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one Ag2O sheet oriented in the (0, 0, 1) direction. Ag1+ is bonded in a 3-coordinate geometry to three equivalent O2- atoms. All Ag–O bond lengths are 2.35 Å. O2- is bonded to six equivalent Ag1+ atoms to form edge-sharing OAg6 octahedra.
Ag2O is Cuprite structured and crystallizes in the cubic Pn-3m space group. The structure is three-dimensional. Ag1+ is bonded in a linear geometry to two equivalent O2- atoms. Both Ag–O bond lengths are 2.10 Å. O2- is bonded to four equivalent Ag1+ atoms to form corner-sharing OAg4 tetrahedra.
Ag2O crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a distorted bent 150 degrees geometry to two equivalent O2- atoms. Both Ag–O bond lengths are 2.17 Å. In the second Ag1+ site, Ag1+ is bonded in a linear geometry to two O2- atoms. There are one shorter (2.09 Å) and one longer (2.12 Å) Ag–O bond lengths. In the third Ag1+ site, Ag1+ is bonded in a linear geometry to two O2- atoms. There are one shorter (2.08 Å) and one longer (2.09 Å) Ag–O bond lengths. In the fourth Ag1+ site, Ag1+ is bonded in a single-bond geometry to one O2- atom. The Ag–O bond length is 2.19 Å. In the fifth Ag1+ site, Ag1+ is bonded in a distorted bent 150 degrees geometry to three O2- atoms. There are two shorter (2.20 Å) and one longer (2.95 Å) Ag–O bond lengths. In the sixth Ag1+ site, Ag1+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are two shorter (2.17 Å) and one longer (2.50 Å) Ag–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to five Ag1+ atoms. In the second O2- site, O2- is bonded in a distorted see-saw-like geometry to four Ag1+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to four Ag1+ atoms.
Ag2O crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. there are three inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a linear geometry to two equivalent O2- atoms. Both Ag–O bond lengths are 2.13 Å. In the second Ag1+ site, Ag1+ is bonded in a linear geometry to two equivalent O2- atoms. Both Ag–O bond lengths are 2.12 Å. In the third Ag1+ site, Ag1+ is bonded to four equivalent O2- atoms to form distorted edge-sharing AgO4 tetrahedra. All Ag–O bond lengths are 2.43 Å. O2- is bonded in a 5-coordinate geometry to five Ag1+ atoms.
The effective capture of volatile radioiodine, a fission product present in used nuclear fuel (UNF), is of paramount importance for development of used fuel reprocessing schemes to prevent release of radioiodine during unit operations and to meet regulatory standards for air emissions. A well-studied method for iodine capture in off-gas streams is the use of silver-functionalized zeolite phases (AgZ), which exploit chemisorption of I to Ag. Advances into other Ag-functionalized materials, including aerogels and metal organic frameworks (MOFs), are underway [1]. Additional metals with the capability to chemisorb iodine, including Cu, Bi, and Sn, [1] are being evaluated as alternatives to Ag for potential applicability to iodine management in off-gas systems. The design of novel functionalized sorbents with Cu and Bi, including composites with metal particles embedded in PAN substrates [2] and composites with metal sulfides embedded in PAN [3], is an ongoing area of study for improved iodine capture. Previously reported work on novel PAN-based metal sorbents has provided the synthesis, characterization, and iodine capture efficiency of this new class of sorbent. Specifically, the metal sulfide PAN composites are found to be easy to produce and reproduce, as well as having a high iodine loading potential under static conditions [3]. Due to the favorable testing previously performed with metal sulfide PAN composites, further testing into the performance of these composites under gas streams containing I2(g) in combination with NO2(g) and H2O(g) is needed. Humid streams of NO2(g) may arise from dissolver off-gas streams, when used fuel is dissolved in HNO3(aq) [4]. NO2(g) has been found to reduce AgZ sorption capacity for I because of oxidation of Ag, the chemisorbing agent, to Ag2O [5]. It follows that performance evaluation of novel sorbents under highly oxidizing conditions such as NO2(g) streams is critical. Therefore, the objective of this study is to determine the effect of flowing NO2(g) and H2O(g) streams on iodine sorption capacity and sorbent performance. This work utilizes custom-built gas handling capabilities for sorbent exposure along with solid-state characterization techniques to assess the physical and chemical properties of sorbents before and after exposure.
The synthesis of fractal Ag oxide (Ag 2 O) on the surface of Ag thin film has been achieved at room temperature by using Synchrotron X-ray irradiation. We have performed an automated quantitative analysis of a batch of 1879 fractal Ag 2 O patterns in a scanning electron microscopy (SEM) image within a radius of 2000 mm outward from the center of the X-ray beam. The morphology is similar to that of the diffusion-limited cluster aggregation (DLCA) model. The fractal dimension (D) of Ag 2 O is between 1.7 and 1.5 from the center to the edge. The area distribution density of fractal Ag 2 O follows a quadratic function with radius R. It is found that the branches’ number of fractal Ag 2 O is a key factor affecting the fractal dimension. The more branches the fractal has, the greater the D is. This is the first time that Ag fractal has been investigated by combining automated data analysis methods with batch experimental data. This data-driven approach provides a new research perspective for rationally regulating materials’ fractal morphology and performance.