Highly efficient and environmental-friendly separation and purification of carbon nanotubes from molten salt via ultrasound-assisted carbonation

Qiao, Zhiqiang; Zhao, Lipeng; Li, Nana; Zhang, Jing; Zhao, Kongkong; Ji, Deqiang; Ji, De–Bin; Yuan, Dandan; Li, Zhida; Wu, Hongjun

doi:10.1016/j.seppur.2022.122630

Cited by 12 publications

(8 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mediating effects of zinc, nickel, and other metals on the CNT formation in electrolytic processes conducted in molten salts have been addressed by Licht et al ,, In all cases, carbon remained adhered to the cathode upon withdrawal and the described sonication and acid removal without observable carbon loss to the salt. More scalable separations including press filtration and carbonation are subject for future research.…”

Section: Results and Discussionmentioning

confidence: 99%

Capture and Electrochemical Reduction of CO₂ Using Molten Alkali Metal Borates

Nitzsche

Bromberg

Hatton

2023

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

Molten alkali metal borates are a class of molten salts that have recently shown promise as high-temperature sorbents for capture of CO 2 and other acid gases. Thermal swing systems based on molten borates have demonstrated CO 2 capture capacities greater than those of amines, enabling efficient recovery of high-temperature heat in flue gas without practical concerns commonly associated with solid sorbents at these temperatures. In this work, we exploited generation of carbonates upon CO 2 capture by borates to enable their use as electrolytic media for carbon nanotube (CNT) synthesis by CO 2 splitting. Here, we report the conditions necessary to synthesize valuable multiwalled CNTs by CO 2 capture and conversion as a sustainable alternative to conventional carbon-intensive CNT synthesis techniques. Effects of cathode materials and operating conditions are quantified in sodium lithium borate, achieving significantly higher CO 2 uptake capacities than alkali metal carbonate salts for conversion of CO 2 into CNTs in the 550−650 °C range.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Capture and Electrochemical Reduction of CO₂ Using Molten Alkali Metal Borates

Nitzsche

Bromberg

Hatton

2023

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…The typical characteristic peak of carbon species can be found at ∼24°in each sample. 36,37 Figure S7a depicts that three sharp diffraction peaks appear in Cu x -PC. It can be determined that the peaks are associated with Cu 0 and Cu 2 O after comparison with the standard cards (JCPDS Nos.…”

Section: Characterizations Of Electrocatalystsmentioning

confidence: 99%

Solar Self-Driven Electrocatalytic Reduction of N₂ Directly to CO₂-Free Generation of Ammonia on a Coupled Ce-Mediated Cu/Porous Carbon Electrode

Li,

Qiao

et al. 2024

ACS Sustainable Chem. Eng.

Self Cite

View full text Add to dashboard Cite

Reduction of nitrogen to ammonia under mild conditions is recognized as one key step in the NH3-economy. The Haber–Bosch process, the typical ammonia production technique, is energy-intensive and high carbon-emitting. Intense efforts have been devoted to searching for sustainable options for decarbonized ammonia generation. Wherein, the electrocatalytic nitrogen fixation route driven by renewable energy is extremely anticipated. Herein, the integrated concept for ammonia production powered by direct solar energy is outlined and proposed. Responding to the limited yield rate and reasonable Faraday efficiency in ammonia synthesis, non-precious Cu-electrocatalysts with porous carbon as substrates are fabricated and Ce is introduced as a modulator which could facilitate electron conduction and nitrogen trapping. By optimizing the proportion of metal sources, strongly synergistic metallic effect of Ce and Cu is structured, further enhancing nitrogen reduction performance of electrocatalysts and inhibiting hydrogen evolution reaction. A satisfactory NH3 yield rate of 30.60 ± 3.04 μg h–1 mgcat –1 is achieved at −0.3 V vs reversible hydrogen electrode (RHE) in 0.1 M KOH and the corresponding FE is about 8.20 ± 0.22%. The solar self-driven NH3 generation system presents a total yield of 104 μg mgcat –1 and a solar-to-ammonia efficiency of 1% at ∼1.2 V in daylight. This work offers a rational energy-utilizing strategy for the preparation of high-grade NH3 chemical via solar system employing non-precious metal catalysts in zero-carbon emission footprint.

show abstract

“…In addition, attributed to the low water solubility of Li 2 CO 3 , CaCO 3 , and BaCO 3 , acid leaching treatment is conventionally used to separate pure carbon products from adhered frozen electrolyte, which can release extra CO 2 by decomposition of carbonate (2H + + CO 3 2– → CO 2 (g) + H 2 O) and therefore decrease the overall CO 2 conversion efficiency. Very recently, some promising joint efforts have been made to achieve a sustainable separation process, such as high-temperature press filtration, ultrasound-assisted carbonation, and an ammonium chloride roasting approach, where the adhered electrolytes can be recycled and reused. However, a more sustainable separation strategy with a reduced carbon footprint is still urgently needed.…”

Section: Cathodic Thermodynamics and Electrochemical Characterizationmentioning

confidence: 99%

Selective CO₂ Electroreduction with Enhanced Oxygen Evolution Efficiency in Affordable Borate-Mediated Molten Electrolyte

Yang

Deng

et al. 2023

ACS Energy Lett.

View full text Add to dashboard Cite

The renewable-electricity-driven carbon dioxide reduction reaction (CO2RR) is potentially a pathway to closing the anthropogenic carbon cycle; however, it is challenging to couple a fast cathodic CO2RR that endows tunable selectivity with a kinetically matched anodic oxygen evolution reaction (OER) at a promising energy efficiency. Here, we report a cost-effective strategy to convert CO2 into C/CO (tunable selectivity of over 70%) with enhanced OER kinetics in water-soluble Na-K-based molten carbonate by modulating the electrolyte’s oxo-acidity using earth-abundant borax (Na2B4O7) as an electrolyte additive, where the borates acting as O2– (an oxo-base) shuttles that constantly mediate between cathode and anode can concurrently facilitate CO2RR and OER. In particular, it can respectively sustain CO2RR at a stable current density of 100 mA cm–2 with a considerable OER current density of ∼300 mA cm–2. The optimal energy efficiency can reach up to over 60%, opening avenues for efficiently manipulating CO2RR and simultaneously enhancing OER.

show abstract

Highly efficient and environmental-friendly separation and purification of carbon nanotubes from molten salt via ultrasound-assisted carbonation

Cited by 12 publications

References 42 publications

Capture and Electrochemical Reduction of CO₂ Using Molten Alkali Metal Borates

Capture and Electrochemical Reduction of CO₂ Using Molten Alkali Metal Borates

Solar Self-Driven Electrocatalytic Reduction of N₂ Directly to CO₂-Free Generation of Ammonia on a Coupled Ce-Mediated Cu/Porous Carbon Electrode

Selective CO₂ Electroreduction with Enhanced Oxygen Evolution Efficiency in Affordable Borate-Mediated Molten Electrolyte

Contact Info

Product

Resources

About

Highly efficient and environmental-friendly separation and purification of carbon nanotubes from molten salt via ultrasound-assisted carbonation

Cited by 12 publications

References 42 publications

Capture and Electrochemical Reduction of CO2 Using Molten Alkali Metal Borates

Capture and Electrochemical Reduction of CO2 Using Molten Alkali Metal Borates

Solar Self-Driven Electrocatalytic Reduction of N2 Directly to CO2-Free Generation of Ammonia on a Coupled Ce-Mediated Cu/Porous Carbon Electrode

Selective CO2 Electroreduction with Enhanced Oxygen Evolution Efficiency in Affordable Borate-Mediated Molten Electrolyte

Contact Info

Product

Resources

About

Capture and Electrochemical Reduction of CO₂ Using Molten Alkali Metal Borates

Capture and Electrochemical Reduction of CO₂ Using Molten Alkali Metal Borates

Solar Self-Driven Electrocatalytic Reduction of N₂ Directly to CO₂-Free Generation of Ammonia on a Coupled Ce-Mediated Cu/Porous Carbon Electrode

Selective CO₂ Electroreduction with Enhanced Oxygen Evolution Efficiency in Affordable Borate-Mediated Molten Electrolyte