Carbon Nanotubes from Carbon Dioxide

N B Singh

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Review article Open Access

Carbon Nanotubes from Carbon Dioxide

N B Singh *

RTDC, Sharda University, Greater Noida, India

*Corresponding author: N B Singh, RTDC, Sharda University, Greater Noida, India,E-mail:

Received: May 9, 2018; Accepted: May 17, 2018; Published: May 18, 2018

Citation: N B Singh (2018) Carbon Nanotubes from Carbon Dioxide. Nanosci Technol 5(1): 1-3.
DOI: 10.15226/2374-8141/5/1/00154

AbstractTop

Green house gas emission particularly emission of CO₂ is a major issue in global warming. Numbers of methods are known to convert CO₂ into useful product. However, recently conversion of CO₂ into CNT is reported. The information is given in this short article.

Introduction

Global warming and global climate changes are due to anthropogenic activities throughout the world [1]. Emissions of greenhouse gases particularly CO₂ gas are responsible for greenhouse effect [2]. CO₂ emissions by different sectors are given in

Figure 1 [3]. Surface temperature is increasing continuously. Therefore, there is an urgent need to develop technologies that will reduce CO₂ emissions.

The easiest way to reduce CO₂ concentrations is to reduce CO₂ emissions through cleaner and more environmentally friendly industrial processes. However, it is not possible in near future. However, there are many ways to reduce CO₂ by converting into number of useful products (Figure 2).

One of the most important nanomaterials is carbon Nanotubes, which can be made from CO₂. There are two types of carbon Nanotubes (Single and double walled carbon nanotubes) (Figure 3). Carbon Nanotubes (CNTs) have been extensively studied due to their unique mechanical, electronic, and thermal properties

Figure 1: CO₂ emissions in 2011

Figure 2: Utilization of CO₂

Figure 3: Carbon Nanotubes

There are number of methods for the synthesis of carbon Nanotubes but the most exciting and new is that by CO₂ [3]. Numerous CO₂ transformation strategies have been proposed to produce CNTs, porous carbon, and graphene using supercritical CO₂ or dry ice [4,5,6].

Li₂CO₃ with trace concentrations of Ni, Cu, Fe or Co dissolve CO₂ to produce CNTs. Figure 4 shows a two chamber where electrolysis and CO₂ dissolution occurs [7,8].

CNTs production by electrolysis in lithium carbonate occurs with the production of oxygen and lithium oxide:

Li₂CO₃ (liquid) ® C (CNT) + Li₂O (dissolved) + O₂ (gas) (1)
Li₂CO₃ consumed in Eq.1 is continuously compensated by

Eq.2.
Li₂O (dissolved) + CO₂ (gas) ® Li₂CO₃ (liquid) (2)
Net reaction (combining Eqs (1) and (2)):
CO₂ (gas) ® C(CNT) + O₂(gas)

Thus from the above reactions CO₂ produced is continuously being consumed to give CNT. This is entirely new and novel process for converting CO₂ into CNT. If this process is commercialized, there will be a breakthrough in global warming.

CNT synthesized using CO₂ is shown in Figure 5 [7,8].

Figure 4: CO₂ to CNT transformation

Figure 5: Synthesis of carbon nanotubes from CO₂ in molten lithium carbonate.

ReferencesTop