Preparation of niobium carbide powder by electrochemical reduction in molten salt

Song, Qiushi; Xu, Qian; Meng, Jingchun; Lou, Taiping; Ning, Zhiqiang; Qi, Yang; Yu, Kai

doi:10.1016/j.jallcom.2015.05.269

Cited by 32 publications

(28 citation statements)

References 21 publications

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“…Actually, the electrodeoxidation of MO x (such as TiO 2 ) to metals (such as Ti) in molten salts typically involves individual reactions. [41][42][43][44][45][46][47][48][49] In comparison with the previous work, 41,44,48,49 the present work suggests that the SOM-assisted electrodeoxidation process can be used to produce MCs with predesigned components from their corresponding stoichiometric MO x /C precursors. [41][42][43][44][45][46][47][48][49] In comparison with the previous work, 41,44,48,49 the present work suggests that the SOM-assisted electrodeoxidation process can be used to produce MCs with predesigned components from their corresponding stoichiometric MO x /C precursors.…”

Section: Reaction Mechanisms Of the Electrodeoxidation Processesmentioning

confidence: 72%

“…Based on the experimental results and the previous studies on the reaction mechanisms of the electrodeoxidation of SiO 2 , TiO 2 , ZrO 2 , and Ta 2 O 5 in CaCl 2based molten salts, [21][22][23][24][25][26][27][28][29][31][32][33][34][35][36][37][44][45][46]48,[52][53][54][55]62 it is reasonable to deduce that the reaction mechanisms of the electrodeoxidation of the MO x /C precursors to MCs in molten CaCl 2 generally contain the chemical/electrochemical compounding, electrodeoxidation, and in situ carbonization processes. The chemical compounding process 25 (MO x + yCaO / Ca y MO (x+y) ) is commonly caused by the CaO presented in the molten CaCl 2 (without being pre-electrolyzed) due to the hydrolysis reaction, i.e., (CaCl 2 $(H 2 O) / CaO (Ca 2+ , O 2À ) + 2HCl).…”

Section: Reaction Mechanisms Of the Electrodeoxidation Processesmentioning

confidence: 95%

“…23,24,38 Therefore, the electrodeoxidation process and the cathodic products produced in the graphite-based anode electrolytic cell are usually inuenced by the abovementioned side reactions. [41][42][43][44][45][46][47][48][49] However, in order to produce MCs, the carbon content of the MO x /carbon (MO x /C) precursors used in the graphite-based anode electrodeoxidation process should be generally higher than the stoichiometric ratios of their corresponding MCs. in the previous work.…”

Section: Introductionmentioning

confidence: 99%

“…40,41 This graphite-based anode molten salt electrodeoxidation process has been used to produce MCs (such as titanium carbide (TiC), silicon carbide (SiC), hafnium carbide (HfC), niobium carbide (NbC), and ZrC, etc.) 44,48,49 Therefore, it is difficult to control the carbon content of the MCs products fabricated using the graphite-based anode electrodeoxidation process. [41][42][43][44][45][46][47][48][49] However, in order to produce MCs, the carbon content of the MO x /carbon (MO x /C) precursors used in the graphite-based anode electrodeoxidation process should be generally higher than the stoichiometric ratios of their corresponding MCs.…”

Section: Introductionmentioning

confidence: 99%

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Solid oxide membrane-assisted controllable electrolytic fabrication of metal carbides in molten salt

Zou

Zheng

et al. 2016

Faraday Discuss.

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Silicon carbide (SiC), titanium carbide (TiC), zirconium carbide (ZrC), and tantalum carbide (TaC) have been electrochemically produced directly from their corresponding stoichiometric metal oxides/carbon (MOx/C) precursors by electrodeoxidation in molten calcium chloride (CaCl2). An assembled yttria stabilized zirconia solid oxide membrane (SOM)-based anode was employed to control the electrodeoxidation process. The SOM-assisted controllable electrochemical process was carried out in molten CaCl2 at 1000 °C with a potential of 3.5 to 4.0 V. The reaction mechanism of the electrochemical production process and the characteristics of these produced metal carbides (MCs) were systematically investigated. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy analyses clearly identify that SiC, TiC, ZrC, and TaC carbides can be facilely fabricated. SiC carbide can be controlled to form a homogeneous nanowire structure, while the morphologies of TiC, ZrC, and TaC carbides exhibit porous nodular structures with micro/nanoscale particles. The complex chemical/electrochemical reaction processes including the compounding, electrodeoxidation, dissolution-electrodeposition, and in situ carbonization processes in molten CaCl2 are also discussed. The present results preliminarily demonstrate that the molten salt-based SOM-assisted electrodeoxidation process has the potential to be used for the facile and controllable electrodeoxidation of MOx/C precursors to micro/nanostructured MCs, which can potentially be used for various applications.

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Section: Reaction Mechanisms Of the Electrodeoxidation Processesmentioning

confidence: 72%

Section: Reaction Mechanisms Of the Electrodeoxidation Processesmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Solid oxide membrane-assisted controllable electrolytic fabrication of metal carbides in molten salt

Zou

Zheng

et al. 2016

Faraday Discuss.

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“…However, most of these methods involve undesirable conditions, such as complicated operation, relatively high temperature, expensive devices, and high vacuum. The literature shows that refractory metals favorably combine with carbon to generate carbides in molten salt, and this has been applied to synthesize tantalum carbides via a relatively simple and economical way. The working temperature to prepare TaC has been effectively decreased (from more than 1200°C to less than 1000°C).…”

Section: Introductionmentioning

confidence: 99%

Electrochemical deposition of tantalum carbide coatings in molten LiCl‐KCl‐K₂CO₃

Song

Meng

et al. 2018

J Am Ceram Soc

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A method for the preparation of tantalum carbide (TaC) coatings on tantalum by electrochemical reduction in carbonate ions in molten LiCl‐KCl was developed. Carbide coatings were obtained on the tantalum substrate at 900°C with a bias voltage of −1.8 V versus the graphite counter electrode. The phase composition, morphology and strength of the carbide coating were characterized by XRD, SEM, and XPS analyses, as well as scratch testing. Kinetic mechanism for the formation of TaC coatings and evolution of chemical bonds between the carbide layer and substrate were schematically discussed. The coatings consist of a single phase of TaC with a thickness of approximately 5 μm. Ta2O5 and tantalate derivatives in molten salt restrict TaC formation. Electro‐deoxidation of Ta substrate can favorably eliminate tantalum‐involved compounds to produce TaC. TaC coatings improve the surface strength of Ta substrate obviously. The formation of a metal‐carbon solid solution in molten salt determines the existence of excess carbon on Ta substrate. Chemical bonds on the TaC coating were investigated in comparison with those at the interface of the metal‐oxygen‐carbon and carbon film.

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Facile Electrochemical Synthesis of Nanoscale (TiNbTaZrHf)C High‐Entropy Carbide Powder

et al. 2020

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High‐entropy alloys and compounds are becoming an important class of new materials due to their outstanding refractory and high‐temperature properties. However, preparation in bulk quantities and in powder form via classical metallurgical methods is challenging. Here, we report the first synthesis of an ultra‐high‐temperature high‐entropy carbide, (TiNbTaZrHf)C, via a facile electrochemical process. In this, a mixture of the individual metal oxides and graphite is deoxidised in a melt of CaCl2 at a temperature of only 1173 K. The (TiNbTaZrHf)C prepared is single‐phase fcc and has a powdery morphology with a particle‐size range of 15–80 nm. Such materials are in demand for modern additive manufacturing techniques, while preliminary tests have also indicated a possible application in supercapacitors. The successful synthesis of (TiNbTaZrHf)C powder may now guide the way towards establishing the electrochemical route for the preparation of many other entropy‐stabilised materials.

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Preparation of niobium carbide powder by electrochemical reduction in molten salt

Cited by 32 publications

References 21 publications

Solid oxide membrane-assisted controllable electrolytic fabrication of metal carbides in molten salt

Solid oxide membrane-assisted controllable electrolytic fabrication of metal carbides in molten salt

Electrochemical deposition of tantalum carbide coatings in molten LiCl‐KCl‐K₂CO₃

Facile Electrochemical Synthesis of Nanoscale (TiNbTaZrHf)C High‐Entropy Carbide Powder

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Preparation of niobium carbide powder by electrochemical reduction in molten salt

Cited by 32 publications

References 21 publications

Solid oxide membrane-assisted controllable electrolytic fabrication of metal carbides in molten salt

Solid oxide membrane-assisted controllable electrolytic fabrication of metal carbides in molten salt

Electrochemical deposition of tantalum carbide coatings in molten LiCl‐KCl‐K2CO3

Facile Electrochemical Synthesis of Nanoscale (TiNbTaZrHf)C High‐Entropy Carbide Powder

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Electrochemical deposition of tantalum carbide coatings in molten LiCl‐KCl‐K₂CO₃