Multifunctional CeO₂ Nanomaterials: Wet Chemical Synthesis, Characterization, and NIR Pigmentation Applications

Abstract

Herein, we report the methods adopted for the syntheses of nano-scale CeO2 materials by wet chemical routes (solution combustion, hydrothermal, and precipitation by NH4OH and mixture of NH4HCO3 and NH4OH) and their experimental results supported by differential thermal analysis, X-ray diffraction, field-emission scanning electron microscopy energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, and near-infrared characterization techniques. The nano-scale CeO2 materials were obtained through wet chemical and simple calcination methods in a single-step process. The thermal profile of precursor salt ((NH4)2Ce(NO3)6) reveals ~72% of weight loss in the temperature ranges from 30 to 800°C, whereas the different as-obtained CeO2 materials showed ~3-13% of weight loss indicating the formation of cubic nanostructured CeO2 materials, as evidenced from XRD patterns. All of the pure materials obtained in a single step crystallized in cubic nanostructured CeO2 phase with the average crystalline sizes in the range of 3–28 nm. The morphology of the combustion obtained CeO2 materials exhibits spherical-shaped fine particles with moderate agglomeration. The as-obtained CeO2 materials can be used in the solar reflective and color pigment applications as it shows remarkably high NIR reflectance in the NIR region, 750–2500 nm compared to other binary oxides.

Efficient Catalytic Hydroformylation of Alkenes on Rh/CeO2 Catalysts Modulated by CeO2 Morphology

“…32 The IR spectra of these samples showed several obvious peaks at 400−800 cm −1 ascribed to the tensile vibration of the Ce−O bond (Figure S1). 33 This indicated the successful preparation of CeO 2 supports with different morphologies. Furthermore, two peaks at 3445 and 1628 cm −1 corresponding to adsorbed water molecules were also observed.…”

Fluidization and Application of Carbon Nano Agglomerations

“…[29][30][31][32] In contrast, nanoparticles prepared by chemical solution methods without sufficient surfactants or strong solid bridge connections are compact hard aggregates. [33,34] Figure 2a shows nanoparticle agglomerates with a loose structure, while Figure 2b,c shows hard and soft agglomerates in nanoparticles respectively. Hard agglomerates are characteristic of non-friable, coarse particles that are difficult to disperse and identified by the connection of spherical or near-spherical particles (Figure 2b, inset), whereas soft agglomerates are friable, easily dispersed and identified via the approach of spherical or near-spherical particles to each other (Figure 2c, inset).…”

Detailed Studies on the Synthesis Methods and Characterizations of Nanocrystalline Cr2O3 Phase Materials for NIR Pigmentation Applications

“…The as-milled reaction mixture of MgFe 2 O 4 composition made from MgO and Fe 2 O 3 precursors annealed at different temperatures (800, 900, 1000, and 1100 °C) showed quite similar trend in increase of NIR reflectance of MgFe 2 O 4 nanomaterials. 47 From previous studies, 20,21,48,49 we learnt that the nano and/or micro-crystalline oxide-based materials reveal high reflectance values in the NIR region owing to different factors such as sample preparation conditions, composition, morphology, refractive index, etc.…”