Influence of the surface layer of hydrated silicon on the stabilization of Co²⁺ cations in Zr–Si fiberglass materials according to XPS, UV-Vis DRS, and differential dissolution phase analysis

Abstract

Two forms of cobalt in fiberglass materials: dimers of Co2+Td in the subsurface layer and isolated Co2+Oh in the bulk.

Morphological, optical and photovoltaic characteristics of MoSe2/SiOx/Si heterojunctions

“…The O 1 s spectrum (Fig. 4c) shows a single peak at 533.0 eV associated with the SiO x layer from the oxidized substrate 28 , thus confirming the absence of secondary phases, such as MoO 3 or MoO 2 . Moreover, the ∼1:2 Mo/Se ratio obtained from integrated peak areas, which were corrected by sensitivity factors, indicates that the MoSe 2 crystals have the desired stoichiometry.…”

Oxygen-Vacancy Engineering of Cerium-Oxide Nanoparticles for Antioxidant Activity

“…The Si occupancy of the Ce sites was also evidenced by the occurrence of the 529.5 eV peak in the Si spectra, attributed to SiO 2 . 25 Additionally, its constant presence throughout the bulk structure indicated successful Si doping into the CeO 2 crystal. The XPS data supported the particle morphologies imaged using TEM (Figure 1).…”

Water diffusion in Zr‐containing fiberglass materials at room temperature

“…To study the water uptake in glass fibers after calcination, two experiments were performed: (a) the rehydration of the sample after calcination at the temperature normally required for preparation of the fiberglass‐supported catalysts; and (b) the rehydration of the sample after calcination in mild conditions (low temperature, vacuum) allowing water removal without the dehydroxylation processes taking place in the bulk of glass fibers and affecting the sample structure . In first experiment, the sample was calcined in air at 450°C for 1 hour.…”

“…These materials are often used as the support for the catalyst preparation . It was shown that the most robust catalysts prepared on the basis of fiberglass materials are those with the active component located in the bulk of glass fibers at a depth of ~10 nm . The anchoring of active component was shown to proceed with participation of OH groups of a glass fiber .…”

“…26 It was shown that the most robust catalysts prepared on the basis of fiberglass materials are those with the active component located in the bulk of glass fibers at a depth of ~10 nm. [26][27][28][29][30][31] The anchoring of active component was shown to proceed with participation of OH groups of a glass fiber. 29 Since the preparation of catalysts (impregnation of uncalcined and calcined fiberglass materials with water solutions of various salts) is performed at room temperature, the understanding of proton distribution and diffusion processes in fibers at room temperature is an important step in developing a scientific basis for the synthesis of such catalysts.…”