## 1 Introduction  
The high consumption of fossil fuels in power plants, automobiles, and various human activities contributes to the dramatically increasing level of carbon dioxide (CO\({}_{2}\)) in the atmosphere [1]. Fossil fuel contributes to about 60% of greenhouse gas emission [2]. Most of the CO\({}_{2}\) emissions (70%) are produced from health production and electricity, agriculture, and industry sectors [3]. The emission of CO\({}_{2}\), in turn, leads to serious environmental and economic problems globally [4; 5; 6]. The high CO\({}_{2}\) level is the main cause of global warming, climate changes, rise in sea and ocean levels, and increased acidity of the water bodies, which has disastrous consequences on the environment [7; 8]. It is predicted that the level of CO\({}_{2}\) in the environment will decrease in the near future since fossil fuels are still the main energy source. Therefore, considerable efforts have been made in order to reduce CO\({}_{2}\) emission and to overcome some of the problems associated with its high concentration in the environment [9; 10; 11]. The CO\({}_{2}\) capture and storage technology is a very common technique to reduce the concentration of CO\({}_{2}\) in the environment [12; 13; 14; 15]. The approach of capturing and storing CO\({}_{2}\) has attracted significant attention from researchers in industry and academia [16; 17; 18]. Although some progress has been made to capture CO\({}_{2}\) using chemical absorbents, such as ethanolamine [19], the process requires high energy, use of volatile absorbents, and high-cost of operation [20]. Therefore, various chemical adsorption techniques have been developed. These are simple and require less energy compared with chemical absorption [21; 22]. The CO\({}_{2}\) adsorbents should exhibit high adsorption capacity (4.4% by weight or \(>\) 1 mol/kg), have long working life, and require low energy for their regeneration and reuse [23]. Recently, various materials were investigated as potential CO\({}_{2}\) adsorbents such as silica [24], zeolites [25], ionic liquids containing imidazolium salt [26], and activated carbon-containing materials [27; 28; 29]. Zeolites, as traditional sorbents, have high thermal and chemical stability and require low energy consumption for regeneration. However, they are strongly hydrophilic and cannot be used for the capture of CO\({}_{2}\) from flue gases [30]. Ionic liquids could be incorporated into a solid matrix in which a heterogeneous system could be used for the capture of CO\({}_{2}\). Carbon-containing materials have high stability, high surface area, easy to modify, and low production cost, but have poor selectivity [31]. The use of carbon-containing materials has been widely studied as potential media for CO\({}_{2}\) capture [27]. Various sources containing carbon, such as biomass, polymers, and resins, have been used to produce activated carbon materials [27]. Both porous volume and surface area of carbon-containing materials could be enhanced using either physical or chemical activation processes [32; 33]. The physical activation process involves the use of a proper gas for carbonization [32]. However, the chemical activation process involves the use of a strong base such potassium hydroxide or potassium carbonate as a chemical activator [33]. The homogeneous distribution of the chemical activator within the carbon-containing materials would improve their adsorption capacity towards CO\({}_{2}\) uptake to a significant level. Various porous nanocarbons were produced and tested as efficient media for the adsorption of CO\({}_{2}\). For example, polyacrylonitrile in the presence of potassium hydroxide led to a CO\({}_{2}\) uptake of 2.74 mmol/g at 25 \({}^{\circ}\)C and 1 bar [28]. The CO\({}_{2}\) uptake was even higher (4.95 mmol/g) at 25 \({}^{\circ}\)C and 1 bar when resorcinol-formaldehyde resin was used as a carbon source in the presence of potassium carbonate as an activator [34].