- Synthesis and characterization of nanostructured MnO2-CoO and its relevance as an opto-electronic humidity sensing device
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Metal carboxylates are widely used in science and technology and have been the subject of intense studies due to the practical importance of their products. The present paper reports the synthesis of MnO2-CoO using metal carboxylates as precursors and the effect of humidity on the transmitted power through its thin film at room temperature. The refractive index of the material was found to be 1.445930 and the peak obtained from the photoluminescence spectra lies in the visible region. TEM reported a minimum grain size of ～5.7 nm and SAED confirmed the crystalline nature of the material, which was further confirmed by XRD. Fluorescence characteristics also confirmed the low dimensionality of the material. The film was then investigated using SEM which exhibited the porous morphology. Through UV-Vis spectroscopy, it was found that the absorption of the film takes place in the UV region and the optical band-gap was observed to be 3.849 eV from the Tauc plot. The film was employed as a transmission based opto-electronic humidity sensor. Average sensitivity was found to be ～2.225 μW/% RH with response and recovery times of 47 s and 59 s respectively. Experiments were repeated and the reproducibility of result was found to be ～89%.
- Sikarwar, Samiksha,Yadav,Dzhardimalieva,Golubeva,Srivastava, Pankaj
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p. 20534 - 20542
(2018/06/14)
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- THE DIRECT ELECTROCHEMICAL SYNTHESIS OF SOME TRANSITION METAL CARBOXYLATES
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The transition metal carboxylates M(O2CR)n (M=Cr, R=C2H5, C6H5, n=3; M=Mn, Fe, Ni, R=CH3, C2H5, C6H5, n-C7H15, n=2, not all combinations) have been prepared by oxidising suitable metal anodes electrochemically in solutions of RCOOH in acetonitrile.With Co and Cu, a wide range of carboxylic acids (R=C2H5, c-C3H5, c-C5H9, C6H5, n-C4H9, n-C7H15, 2-ethylhexanoic, oleic, linoleic) has been used succesfully to give M(O2CR)2.The advantages of the method are discussed.The preparation of Cu(O2CR)2 involves the prior formation of CuO2CR at the anode, followed by oxidation by the solvent.
- Kumar, N.,Tuck, Dennis G.,Watson, Katherine D.
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p. 740 - 743
(2007/10/02)
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- Liquid phase air oxidation process for making phthalic acids
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An improvement in the liquid phase air oxidation process based upon a solvent system such as acetic acid and with a bromine activated heavy-metal catalyst system for preparing phthalic, isophthalic and terephthalic acids from their corresponding alkyl benzenes wherein the heavy metal is a soluble cobalt compound and sufficient excess of air is introduced so that the waste gas still contains an excess of oxygen.
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