SAXS Study of the Structure of Fibrous Ceric Hydrogen Phosphate Gels
- PDF / 502,695 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 57 Downloads / 127 Views
AXS Study of the Structure of Fibrous Ceric Hydrogen Phosphate Gels S. V. Amarantova, T. O. Shekunovab, c, *, A. E. Baranchikovb, and V. K. Ivanovb, c a
Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” Russian Academy of Sciences, Moscow, 119333 Russia b Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, 119991 Russia c Department of Material Sciences, Moscow State University, Moscow, 119991 Russia *e-mail: [email protected] Received July 23, 2019; revised August 27, 2019; accepted August 29, 2019
Abstract—Gel-like ceric hydrogen phosphates with unusual 1D fibrous structure are known since the end of 19th century. Nevertheless, the structure of these materials is still poorly understood. Here we first have applied small angle X-ray scattering (SAXS) technique to get a deeper insight into the structure of wet ceric hydrogen phosphate gels synthesized from ceric phosphate solutions with various cerium concentration. To interpret SAXS data, we used a structural model considering interparticle interaction. The quantity of independent model parameters was determined by the number of independent singular vectors and by the number of Shannon channels. Finally, key parameters characterizing the scattering from gels have been determined. Keywords: small angle X-ray scattering, gels, ceric hydrogen phosphates DOI: 10.1134/S1027451020070034
INTRODUCTION Sol-gel chemistry opens wide possibilities in the design of inorganic materials by different ordering in initial solutions [1]. Most often, the sol-gel approach is used to obtain materials consisting of isotropic metal oxide nanoparticles. A classic example is the synthesis of amorphous silicon dioxide by hydrolysis and condensation of the alkoxide-based precursor [2]. In turn, there are only few examples of inorganic materials consisting of 2D structural units obtained by the solgel method. In particular, these are materials based on graphene [3] or MoS2 sheets [4], which are in high demand in electrochemistry due to their outstanding electronic conductivity, high charge mobility, and large specific surface area. The 1D inorganic materials obtained by the direct template-free sol-gel method have been scarcely studied. Known examples include vanadium pentoxide gels derived from neutral VO(OH)3 species or vanadium alkoxide precursors [5], AgVO3 nanofibers gel [6], and cerium(IV) hydrogen orthophosphate gels. The latter are the most intriguing since the formation of gels from poorly soluble complex inorganic compounds, in particular orthophosphates of rare-earth elements, is complicated because of their low solubility, which should result in their rapid precipitation. Gel-like cerium(IV) hydrogen orthophosphates have been poorly studied, despite the fact that they are known since the end of the 19th century. Their synthe-
sis was first described by Hartley in 1882 [7]. However, subsequent interest in these compounds arose only in the middle of the 20th century, when ion
Data Loading...
