Effect of Co2+ and Ni2+-doped zinc borate nano crystalline powders by co-precipitation method

Shim, Jaesool; Reddy, Ch. Venkata; Sarma, G.V.S.S.; Murthy, P. Narayana; Ravikumar, R.V.S.S.N.

doi:10.1016/j.saa.2015.02.008

Cited by 16 publications

(6 citation statements)

References 24 publications

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“…The comparison plot of three nickel manganese oxides and individual oxides such as NiO and Mn 2 O 3 exhibited Raman band within the range 350–2000 cm −1 . Generally bands below ∼600 cm −1 can be assigned to a symmetric stretching vibration of metal‐oxygen groups, and we observed Ni−O stretching at 364 cm −1 . A broadened and weak band from ∼450 to 650 cm −1 is found in all the catalysts, which is related to the vibration of the Mn−O band.…”

Section: Resultsmentioning

confidence: 53%

“…The comparison plot of three nickel Generally bands below~600 cm À 1 can be assigned to a symmetric stretching vibration of metal-oxygen groups, and we observed NiÀ O stretching at 364 cm À 1 . [35] A broadened and weak band from~450 to 650 cm À 1 is found in all the catalysts, which is related to the vibration of the MnÀ O band. The small peaks at 560 and 619 cm À 1 denote MnÀ O octahedral and MnÀ O tetrahedral sites, respectively, that show good agreement with the literature.…”

Section: Characterization Of Bimetallic Oxidesmentioning

confidence: 87%

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Electrochemical Oxidation of Glycine with Bimetallic Nickel−Manganese Oxide Catalysts

et al. 2020

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A simple template-free hydrothermal route followed by hightemperature (800°C) annealing in air forms Ni-Mn bimetallic oxides, namely NiMn 2 O 4 , Ni 1.5 Mn 1.5 O 4, and MnNi 2 O 4, which are characterized by XRD, Raman, EDS, and SEM analysis. The electrocatalytic activity of these metal oxides toward the oxidation of glycine molecules in alkaline condition was studied by cyclic voltammetry and linear sweep voltammetry methods. Among other nickel manganese bimetallic oxides and monometallic oxides (Mn 2 O 3 , NiO), Ni 1.5 Mn 1.5 O 4 shows excellent redox characteristics with high oxidation current density (310 μA cm À 2 at 0.43 V vs. Ag/AgCl) and lower onset potential (0.22 V vs. Ag/ AgCl). Additionally, Ni 1.5 Mn 1.5 O 4 exhibits a moderate Tafel slope (78 mV dec À 1 ) and is electrochemically stable, as confirmed from chronoamperometry, indicating its potential for glycine oxidation. The linear dependence of the oxidation current with glycine concentration signifies that the overall process is diffusion controlled. The electrochemical results suggest that bimetallic mixed Mn and Ni oxides are promising glycine oxidation catalysts, which may be attributed to the cooperative effect between different Ni and Mn elements.[a] R.

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Section: Resultsmentioning

confidence: 53%

Section: Characterization Of Bimetallic Oxidesmentioning

confidence: 87%

Electrochemical Oxidation of Glycine with Bimetallic Nickel−Manganese Oxide Catalysts

et al. 2020

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“…The band at 403 cm −1 was assigned to the Ni-O stretching mode, which was difficult to observe. Bands below 600 cm −1 were due to the symmetric stretching vibration of metal-oxygen groups 79 , while ZIF-8 showed no apparent absorption in this region. These facts suggest that NiO and PTA were present in the catalysts.…”

Section: Resultsmentioning

confidence: 95%

NiO-PTA supported on ZIF-8 as a highly effective catalyst for hydrocracking of Jatropha oil

Liu

Wang

et al. 2016

Sci Rep

125

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Nickel oxide (NiO) and phosphotungstic acid (PTA) supported on a ZIF-8 (NiO-PTA/ZIF-8) catalyst was first synthesized and it showed high activity and good selectivity for the hydrocracking of Jatropha oil. The catalyst was characterized by SEM, SEM-EDS, TEM, N2 adsorption, FT-IR, XRD and XPS. Compared with the NiO-PTA/Al2O3 catalyst, the selectivity of C15-C18 hydrocarbon increased over 36%, and catalytic efficiency increased 10 times over the NiO-PTA/ZIF-8 catalyst. The prepared NiO-PTA/ZIF-8 catalyst was stable for a reaction time of 104 h and the kinetic behavior was also analyzed. This catalyst was found to bypass the presulfurization process, showing promise as an alternative to sulfided catalysts for green diesel production.

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“…Blue glass has absorption bands at about 524, 596 and 650 nm, which are characteristic of Co 2+ in a tetrahedral environment, easily enabling the identification of cobalt as the blue pigment. These absorption bands derive from the allowed electronic 3d 7 transitions of Co 2+ cations (from the 4 A 2 (F) ground state to the 4 T 1 (P) and 2 T(G) excited states) characteristic of cobalt in tetrahedral sites [237][238][239]. In a weak octahedral crystal field Co 2+ (d 7 ) gives rise to quartet states 4 T 1g (F), 4 T 2g (F), 4 A 2g (F) and 4 T 1g (P) and a number of doublet states like 2 A 1g (G), 2 T 1g (G), 2 T 2g (G) and 2 E g (G) of which 4 T 1g (F) is the ground state.…”

Section: Optical Spectroscopic Non-invasive Characterization Of Colouring Phases and Glassy Silicate Matrixmentioning

confidence: 99%

Cobalt and Associated Impurities in Blue (and Green) Glass, Glaze and Enamel: Relationships between Raw Materials, Processing, Composition, Phases and International Trade

2021

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Minerals able to colour in blue (and green in combination with yellow pigments) are limited in number and geologically. After presenting a short history of the use of cobalt as a colouring agent of glass, glaze and enamel in the Western/Mediterranean, Islamic and Asian worlds since Antiquity, we will present the different forms (dissolved ions, natural and synthetic crystalline phases/pigments) of cobalt and associated elements regarding primary (transition metals) and secondary geological deposits (transition metals and/or arsenic, bismuth, silver). Attempts to identify the origin of cobalt have been made by many authors considering the associated elements but without considering the important modifications due to different processing of the raw materials (extraction/purification/formulation). We review the information available in the ancient reports and present literature on the use of cobalt, its extraction and production from the ores, the different geological sources and their relationship with associated elements (transition metals, bismuth, arsenic, and silver) and with technological/aesthetic requirements. (Partial) substitution of cobalt with lapis lazuli is also addressed. The relative application of non-invasive mobile Raman and pXRF analytical instruments, to detect mineral phases and elements associated with/replacing cobalt is addressed, with emphasis on Mamluk, Ottoman, Chinese, Vietnamese and Japanese productions. The efficiency of Ni-Zn-As diagram proposed by Gratuze et al. as a classification tool is confirmed but additionally, CoO-Fe2O3−MnO and CoO-NiO-Cr2O3 diagrams are also found as very efficient tools in this research. The relationship between the compositional data obtained from the artefacts and historical questions on the origin and date of their production are discussed in order to obtain a global historical view. The need of a better knowledge of (ancient) deposits of cobalt ores and the evolution of cobalt ore processing with time and place is obvious.

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Effect of Co2+ and Ni2+-doped zinc borate nano crystalline powders by co-precipitation method

Cited by 16 publications

References 24 publications

Electrochemical Oxidation of Glycine with Bimetallic Nickel−Manganese Oxide Catalysts

Electrochemical Oxidation of Glycine with Bimetallic Nickel−Manganese Oxide Catalysts

NiO-PTA supported on ZIF-8 as a highly effective catalyst for hydrocracking of Jatropha oil

Cobalt and Associated Impurities in Blue (and Green) Glass, Glaze and Enamel: Relationships between Raw Materials, Processing, Composition, Phases and International Trade

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