The N2 sorption isotherm of garlic roots-derived activated carbon (GR-AC) shows a combination of a type I and type IV isotherms (Figure ). The steep uptake at low relative pressure (P/Po ≤ 0.01) indicates that the majority of adsorption takes place in the micropores (type I). At P/Po > 0.4, the curve shows a hysteresis loop, indicating the presence of mesopores along with micropores (type IV). The hysteresis loop at higher relative pressures is commonly observed due to capillary condensation in the mesopores. The BET surface area (SBET) and microporous surface area (Smicro) of GR-AC is determined to be 1464 m 2 g -1 and 1208 m 2 g -1 , respectively. The pore size distribution curve shows a range of pore sizes between 1-15 nm (Figure ), with pore volumes of 0.75 cm 3 g -1 (Vtotal) and 0.47 cm 3 g -1 (Vmicro), respectively. The SSA performance of the garlic roots-derived activated carbon (GR-AC) electrodes was investigated by coupling the galvanostatic charging and discharging (GCD) cycles with CO2 concentration measurements. The experimental setup used for SSA experiments is discussed in the supporting information (section S4 and Figure ). The GCD curves and CO2 concentration measurements in Figure show that for all voltage windows, charging the supercapacitor leads to adsorption of CO2 while discharging the supercapacitor leads to desorption of CO2. A concentration decrease from 15 % to 5 % is observed during charging from 0 V to -1 V (Figure ). After reaching the minimum concentration, the CO2 concentration returns close to the equilibrium value during the potential holding step at -1 V. A holding time of 120 min was needed to achieve the full saturation and maximum adsorption capacity of the electrodes (Figure ). Similarly, an increase in concentration from 15 % to 31 % is observed during discharging the supercapacitor from -1 V to 0 V followed by a voltage holding step at 0 V to allow complete desorption of CO2. At increased voltage windows, the minimum CO2 concentration reaches 4.8 %, 3.8%, and 3.3 % at -1.2 V, -1.4 V, and -1.6 V while the maximum concentration increased to 36 %, 40 %, and 41 %, respectively upon discharging to 0 V from respective voltages. The desorption curves show a sharp transition after reaching the maximum concentration at all voltage windows and attain the equilibrium concentration of ca. 15% during the 60 minutes of holding time. However, the adsorption curves are broader and return only slowly to the original CO2 concentration, suggesting that adsorption is slower than desorption. This effect is more pronounced at higher voltage windows of -1.2 V, -1.4 V, and -1.6 V, and the maximum adsorption capacity is not reached after the 90 minutes holding time. These results can be understood through the ionic liquid-solid mechanism of SSA which assumes that CO2 hydrolyses in the electrolyte to form H + , HCO3 -, and CO3 2-ions that can adsorb to the double layers of the positive electrode (as HCO3 -, CO3 2-) and the negative electrode (as H + ) upon charging. The H + ions have smaller size, higher charge-density, and higher mobility compared to Na + ions and their preferential adsorption to the double layer increases the pH of the bulk solution. The increase in pH upon charging shifts the CO2(aq)/HCO3 -equilibrium towards HCO3 -, leading to depletion of CO2 from the solution, which leads to additional CO2 dissolution from the gas phase to the solution, until the chemical equilibrium is re-established. Application of higher voltage windows results in higher charge storage in the electrodes explaining the increased amount of CO2 captured. Upon discharging, the desorption of respective ions from the solution shifts the chemical equilibria, leading to increased concentration of CO2 in the effluent stream. The rate constant for CO2 hydrolysis is known to be smaller than for the reverse reaction, explaining the faster desorption. The effect is possibly more pronounced at higher voltage windows because first more easily accessible larger pores are utilized, and less accessible, smaller pores are only used closer to the final voltage.