Thermal Decomposition Studies of Layered Metal Hydroxynitrates (Metal: Cu, Zn, Cu/Co, and Zn/Co)

Abstract

Layered metal hydroxynitrates and mixed metal hydroxynitrates (copper/cobalt hydroxynitrates and zinc/cobalt hydroxynitrates at different mole ratios) were synthesized by hydrolysis of urea and metal nitrates at 140°C. Layered metal hydroxyl nitrates derive their structure from brucite mineral and generally crystallize in hexagonal and monoclinic phases. Isothermal decomposition studies of Cu2(OH)3(NO3), Co2(OH)3(NO3), Cu1.5Co0.5(OH)3(NO3), Cu1.34Co0.66(OH)3(NO3), Zn5(OH)8(NO3)2(H2O)2, Zn3.75Co1.25(OH)8(NO3)2(H2O)2, and Zn3.35Co1.65(OH)8(NO3)2(H2O)2 samples were carried out at different intervals of temperature and the structural transformations during the process were monitored using powder X-ray diffractograms. Biphasic mixture of metal hydroxynitrate/metal oxide is observed in case of cobalt/zinc based layered hydroxynitrates, while copper hydroxynitrate or copper/cobalt metal hydroxynitrate decomposes in a single step. The decomposition temperatures of layered metal hydroxynitrates and mixed layered metal hydroxides depend on the method of preparation, their composition and the nature of metal ion, and their coordination.

CuO/ZnO Heterojunction Nanorod Arrays Prepared by Photochemical Method with Improved UV Detecting Performance

“…Combined with the XRD analysis, the resultant is monoclinic CuO crystal. The thermal analysis results of the decomposition reaction are in accordance with many reports [34,35].…”

Effects of zinc precursor, basicity and temperature on the aqueous synthesis of ZnO nanocrystals

“…7, b) shows the complete disappearance of the NLP phase that decomposes into a mixture of ZnO and monoclinic Zn 3 (OH) 4 (NO 3 ) 2 (S.G : P21/C) having a most intense peak appearing at 12.9°and corresponding to d (100) . 43 The XRD patterns of the sample heated at 200°C and 250°C (Fig. 7, c and d) show the disappearance of Zn 3 (OH) 4 (NO 3 ) 2 and the formation of wurtzite zinc oxide which exhibits intense and well-defined diffraction peaks indicating the improved crystallization of ZnO nanocrystals after annealing at these temperatures.…”

Three-Dimensional Functionalized Boron Nitride Nanosheets/ZnO Superstructures for CO2 Capture

“…In step 2, the evaporation-induced solvothermal route I was employed to prepare cubic FBNNSs/ZnO/Zn 2 (OH) 3 NO 3 superstructures by the analysis of XRD result in Figure S3a. Surprisingly, the precursors could be transformed into FBNNSs/ZnO with original cubelike structures (Figures S3b and S4) via the annealing treatment in air ascribed to the thermal decomposition . Furthermore, SEM images (Figure b,c) demonstrated that the size of c-FBNNSs/ZnO was around 20–50 μm and Figure d validates that the FBNNSs stacked horizontally on the surface of inner cubic ZnO core to form the outside coating.…”