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Applications
Published in Alan Jones, Brian McNicol, Temperature-Programmed Reduction for Solid Materials Characterization, 2014
Solid solutions of atomic-ratio Co/Rh = 1 were made by oxidation of evaporated mixed salts of Co and Rh at 1073 K for 48 h [33]. The TPR profile of this material is shown in Fig. 12. The material CoRhOx reduced in a single peak in the temperature range 453-523 K. The hydrogen consumption was equivalent to that expected for a mixed oxide of composition CoRh2O4 and Co3O4. XRD showed the mixed oxide to consist of these components. The fact that the TPR is a single peak at a temperature lower than that for cobalt oxide indicates that the phase- separated Co3O4 is in intimate contact with CoRh2O4 and that the latter acts as a catalyst for the reduction of the cobalt oxide.
Microsupercapacitors
Published in Ling Bing Kong, Nanomaterials for Supercapacitors, 2017
Ling Bing Kong, Wenxiu Que, Lang Liu, Freddy Yin Chiang Boey, Zhichuan J. Xu, Kun Zhou, Sean Li, Tianshu Zhang, Chuanhu Wang
Cobalt oxide films (Co3O4) were deposited by using a sputtering technique, with different sputtering gas-ratios of O2/(Ar+O2), to evaluate the effects on microstructural properties and thus electrochemical performances [20]. The Co3O4 thin films were used to assemble all solid-state thin-film supercapacitors (TFSCs), with the Co3O4 as electrodes and an amorphous LiPON thin-film as electrolyte. The Co3O4/ LiPON/Co3O4 TFSCs exhibited a bulk-type supercapacitor behavior. It was found that electrochemical performance of the TFSCs could be optimized through the sputtering gas-ratio.
Novel Vanadia/meso-Co3O4 catalysts for the conversion of benzene–toluene–xylene to environmental friendly components via catalytic oxidation
Published in Environmental Technology, 2023
E. Shamma, S. Said, M. Riad, S. Mikhail
TGA profiles of m-Co3O4(x) & 1 &6 wt.%V2O5/m-Co3O4(1.0) samples were depicted in Figure 8. Three weight-loss steps can be noticed in the TGA profile of m-Co3O4(x) (Figure 8(A)). The first step up to ∼ 150 °C was attributed to the removal of physically adsorbed water on the surface of m-Co3O4(x), with weight loss ∼ 3.0, 1.6, and 1.0% for m-Co3O4(0.5), m-Co3O4(1.0), and m-Co3O4(2.5), respectively. The second step in the temperature range 200–450 °C was related to the removal of adsorbed surface Oxygen species, including surface −OH, O−, O2– and chemically adsorbed water. As the Cobalt mol ratio increases, the weight loss increases from 1.2 to 1.3% but sharply decreases to 0.9% for the m-Co3O4(2.5) sample. Accordingly, the m-Co3O4(1.0) sample possessed the highest content of active Oxygen species contributed in the oxidation reaction. The third one observed at a temperature range 450–700 °C, which accompanied the removal of the lattice Oxygen of Co3O4 and transformation of Co3+ to Co2+ as follows: Co3O4 → 3CoO + ½O2, hence the decomposition of Co3O4 into CoO. The third weight losses were 0.95, 1.0, and 1.1% for m-Co3O4(0.5), m-Co3O4(1.0), and m-Co3O4(2.5), respectively [51]. The total weight loss of the three samples was 3, 3.9, and 5.1% for m-Co3O4(2.5), m-Co3O4(1.0), and m-Co3O4(0.5), respectively.