Self-Organized Assembly of Copper Oxalate Nanocrystals

Abstract

Copper oxalate has been precipitated in water and acetone. Raman spectroscopy is performed to validate the chemical composition of the obtained powders. Aqueous precipitation has led to micrometer-scaled agglomerates, whereas acetone precipitation has led to nanorods showing a two-dimensional (2D) selforganization when deposited on a Si substrate. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show an anisotropic structure of the agglomerates with two kinds of faces. Nanoplatelets with self-assembly abilities are also detected in the copper oxalate aqueous suspension. These observations reveal a supracrystalline self-assembly process leading to micrometer-scaled three-dimensional (3D) superstructures. AFM measurements on nanoplatelets and nanorods are correlated to X-ray diffraction results. A kinetic study carried out by SEM highlights four main steps in the 3D self-assembly process. Each step corresponds to a specific assembly speed ratio between the two directions that define the superstructures. Additives like hydroxypropylmethylcellulose (HPMC) and glycerin modify this speed ratio and therefore allow the shape of the supracrystals to be controlled.

Non-precious cobalt oxalate microstructures as highly efficient electrocatalysts for oxygen evolution reaction

“…As shown in Fig. 8a, CoC 2 O 4 $2H 2 O MRs display prominent peaks at 132, 202, 221, 250, 530, 589, and 914 cm À1, which agree well with the previously reported metal oxalates [50][51][52]. Aer OER measurements, these peaks completely disappeared along with the appearance of three new peaks at 677, 515 and 468 cm À1 corresponding to CoOOH [53][54][55].…”

Preparation, characterization and catalytic effects of copper oxalate nanocrystals

“…The suspension was kept under permanent stirring and the temperature was regulated to 40 • C. The suspension was vacuum filtered, dried at 80 • C for 12 h then washed with ethanol, finally filtered and dried again at 80 • C for 12 h [22] to get CuC2O4 nanocrystals. …”

Synthesis of nanostructured copper oxide via oxalate precursors and their sensing properties for hydrogen cyanide gas

“…Copper oxalate precursors with varied hierarchical morphologies were prepared by chemical solution deposition only through tuning reagents concentrations, which were then calcinated to produce hierarchical nanostructured CuO products. [35][36][37][38][39] The high surface area CuO functionalized QCM sensors showed excellent sensing properties to HCN.…”