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 TG-DTA, XRD, FESEM-EDX, FT-IR, and NIR characterization techniques. The nano-scale CeO2 materials were obtained through wet chemical and simple calcination methods in a single-step process. The thermal (TG) profile of precursor salt ((NH4)2Ce(NO3)6) reveals ∼72% of weight loss in the temperature ranges from 30 °C 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 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. The visual appearance of the as-obtained CeO2 powder was pale yellow color and varied with the preparation conditions. The FT-IR band observed at ∼490–534 cm−1 for all the as-obtained CeO2 materials confirming the metal oxide network, Ce–O.