Adsorption and Photo-catalytic Properties of Congo Red by Cobalt Doped Porous ZnO Prepared Through Hydrothermal Method

ZnO and cobalt doped ZnO were prepared by hydrothermal method with zinc acetate dihydrate, cobalt acetate tetrahydrate and urea as raw materials and sodium citrate as surface modifier. Congo red (CR) was used as the pollutant model for adsorption and photo-catalytic experiments. Under the same conditions, the adsorption effect of cobalt doped ZnO with different urea content on CR was investigated, and the optimum urea content was determined. Under the same conditions, the adsorption and photocatalytic properties of cobalt doped ZnO prepared with the best urea content at different annealing temperatures were studied. According to the analysis of experimental data, the adsorption effect of Co doped ZnO with urea content of 8mmol and annealing temperature of 300℃ is the best, and the photocatalytic effect is also the best under the same conditions.

Metal-mediated reactions towards the synthesis of a novel deaminolysed bisurea, dicarbamolyamine

A new selective cobalt acetate tetrahydrate or cerium nitrate hexahydrate mediated cleavage of the C–N bond of a benzoyl isothiocyanate derivative to give (carbamoylamino)methanethioamide is presented. The cleavage of the C–N could not be achieved in the absence of thione. The novel silver-mediated conversion of a thione to the carbonyl was achieved on 1-((benzamido)formyl)urea and replicated on (carbamoylamino)methanethioamide to give the deaminolyzed bisurea (dicarbamolyamine). The compounds were characterized by IR, NMR, microanalysis and GC–MS. The single crystal X–ray diffraction studies of the crystal structures of compounds I, II, III and V is discussed.

Mechanism of thermal decomposition of cobalt acetate tetrahydrate

The thermal decomposition of cobalt acetate tetrahydrate (Co(CH3COO)2 · 4H2O) has been studied via thermogravimetric (TG) analysis, in situ X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results of TG and XRD showed that the parent salt melted and then the dissolved crystalline water was vaporized in two steps. The dehydration process was followed by a major step concerning the decomposition of the acetate group, leading to basic acetate as an intermediate, which then produced CoO and Co in N2 and H2 atmosphere, respectively. Three decomposition intermediates Co(CH3COO)2 · 0.5H2O, Co(CH3COO)2, and Co(OH)(CH3COO) were presumed. In situ XRD experiments revealed that the intermediate basic acetate was poorly crystallized or even amorphous. Evolved gases analysis indicated that the volatile products of acetate decomposition were water vapor, acetic acid, ethylenone, acetone, and CO2. A detailed thermal decomposition mechanism of Co(CH3COO)2 · 4H2O was discussed.