Layered Hydroxide Metal Acetates (Metal = Zinc, Cobalt, and Nickel): Elaboration via Hydrolysis in Polyol Medium and Comparative Study

Abstract

Layered hydroxide metal acetates (metal ) zinc, cobalt, and nickel) have been prepared by a new route belonging to the chimie douce method. This novel method involves the hydrolysis, in polyol medium, of in situ-formed complexes supposed to be alkoxyacetates. These layered hydroxide metal acetates present poorly ordered character, and their X-ray patterns have features typical of lamellar compounds with turbostratic disorder. Their chemical formula was established to be M(OH) 2-x (CH 3 COO) x ‚nH 2 O with (x, n) ) (0.42, 0.31), (0.38, 0.53), and (0.40, 0.63) for Zn, Co, and Ni, respectively. The layered hydroxide nickel acetate has a classical brucite structure with a random substitution of some hydroxyl groups by acetate groups. The layered hydroxide zinc and cobalt acetates are isomorphous with the hydrozincite structure, in which cations are located in both octahedral and tetrahedral sites. The acetate anion behaves as a unidentate ligand in LHS-Ni and LHS-Co, where LHS indicates layered hydroxide salt, and is intercalated as a free anion in the zinc compound. The dehydration is a reversible topotactic process for LHS-Ni and Co, whereas it is a destructive process in the case of LHS-Zn.

Simple non-basic solution route for the preparation of zinc oxide hollow spheres

“…The diffraction pattern obtained at 120 1C ( Fig. 1(a)) agrees well with that of layered hydroxide of zinc acetate (LHZA) having features of lamellar compounds related to brucite-type layers [37]. The LZHA exhibited layered structures as evidenced from their X-ray diffraction (XRD) patterns, which showed intense (0 0 l) diffraction peaks in the low angle range and asymmetric reflections in the range of high angles.…”

Deposition of Zinc Oxide and Layered Basic Zinc Salts from Aqueous Solutions Containing Amino Acids and Dipeptides

“…26 ,27 The resulting diffraction pattern consists of sharp reflections in the range of small diffraction angles and broad asymmetric peaks at high angles. 26 These reflections correspond to the 00l and hk0 peaks, respectively, as all of the mixed hkl peaks are suppressed completely by the randomness in translation and rotation.…”

ZnO nano-rectangular framework-like structure from zinc hydroxide acetate plates

“…They can be indexed in the hexagonal system referring to the data indicated in ICDD 56-569. 22) However, an angle between the [100] direction and the long side of the rectangle plate is slightly different between Figs. 3(a) and 3(b).…”

“…The crystal growth is very interesting compared with the morphologies found in previous studies involving LHZA. 22)26) The subsequent pyrolysis reaction results in a nano-framework-like morphology formed through a self-assembly process. Our approach can facilitate the crystal growth of the self-template metal hydroxides and the pyrolysis reaction to form the metal oxides, which is regarded as a unique system of the morphology control.…”