Spectroscopic and structural properties of CeO2 nanocrystals doped with La3+, Nd3+ and modified on their surface with Ag nanoparticles

Abstract

The purpose of this work is to present our efforts focused on applications of chemical synthesis of nanocrystalline cerium dioxide (CeO 2 ) powders doped with La 3þ ions and CeO 2 :Nd 3þ modified, on their surface, with Ag nanoparticles (NPs). The synthesized powders were examined by X-ray powder diffraction (XRD), absorption, emission spectroscopy, scanning electron (SEM) and atomic force microscopy (AFM). The relations between crystallographic properties and stability of CeO 2 compounds doped by La ions and surface-modified by Ag were studied. XRD patterns revealed that all studied samples are single-phase and crystallized in the cubic fluorite-type structure, in space group Fm-3m. The average crystallite sizes estimated by Rietveld method of series: La-doped CeO 2 were in the range of 7-14 nm, and CeO 2 :1%Nd 3þ /n-Ag (n: 1-5wt.%) were found to be in the range of 29-34 nm, respectively. The lattice parameter a for La-doped CeO 2 powders varying from 5.416 to 5.482 Å with increasing content of La 3þ ions from 0 to 20wt.%, respectively. For series of CeO 2 :Nd 3þ /n-Ag materials lattice parameter a was at the same level and in accordance with the standard value a 0 ¼ 5.411 Å (ICDD -43-1002). The SEM and AFM observations depicted the grainy structure of all obtained CeO 2 -powder samples. The estimated grain size ranged from 50 to 500 nm. The diverse grain shapes and packing was remarked in the samples. According to our knowledge, the relationship between the structural, spectroscopic and morphological characteristics of CeO 2 samples was presented in this work for the first time.

Interface Engineering of the Cu1.5Mn1.5O4/CeO2 Heterostructure for Highly Efficient Electrocatalytic Nitrate Reduction to Ammonia

“…X-ray diffraction (XRD) analysis is further performed to determine the crystal and phase structure of the obtained products (Figure a). All intense diffraction peaks of the CMO are intense and can be indexed as Cu 1.5 Mn 1.5 O 4 (PDF #35-1172), implying its good crystallinity. − When the CMO is coupled with CeO 2 , the diffraction peaks of both CMO (PDF #35-1172) and CeO 2 (PDF #43-1002) are observed, confirming the successful formation of the CMO/CeO 2 heterostructure. − Moreover, it can be seen that, as the CeO 2 ratio increases, its diffraction peaks gradually strengthen. The refined XRD pattern of the CMO/CeO 2 -2 heterostructure is shown in Figure b.…”

Bimetallic CoCeO2 oxide nanoparticles: An efficient and reusable heterogeneous catalyst for the preparation of 2‐amino‐3‐cyano‐4H‐pyran derivatives

“…Cerium oxide (CeO 2 ) nanoparticles (NPs) are becoming well-known for their distinctive structures and their special chemical and physical characteristics. The broad applicability of CeO 2 NPs to numerous areas such as gas sensors, optoelectronics, fuel cell technologies, microelectronics, photocatalysis, and solid-state electrolytes [5][6][7][8][9][10]. Various methods are reported in literature for the preparation of CeO 2 NPs, such as combustion synthesis, sonochemical synthesis, chemical reduction, self-assembly processes and sol-gel synthesis and used as catalysts.…”