## 4 Results and Discussion
Consequently, the capillary condensation effect occurs more significantly  
Figure 6: TEM photomicrographs of different MWCNT/AC-RFA mixed sample compositions; namely **(a)** S100, **(b)** S60, **(c)** S50, **(d)** S40 and **(e)** S0. in AC-RFA than MWCNTs; and the results listed in Table S2 (Supplementary Materials) support this behavior. Overall, as is reported in the literature, there are five types of hysteresis loops and their related pore shapes. Namely, Type-A is attributed to cylindrical pores; Type-B is assignable to slit pores; Types-C and -D are assignable to wedge shaped pores and Type-E is attribute to bottle neck pores [43]. The hysteresis loops in this work belong to Type-E, which indicates to bottle neck pore type. Through the results listed in Table 1, it is seen from the S60 to S0 samples that the neck of the mesopore opens at a \(P/P_{o}\) range between \(\sim\)0.7 and 1; as shown by the observed hysteresis loops [44]. This indicates that all the samples from S60 to S0 exhibit mesoporous structures. The pore volume of samples changed from 0.026 to 0.767 cm\({}^{3}\)/g when comparing S100 to S0, respectively; and the average pore size changed from 63.7 to 6.1 nm when comparing S100 to S0, respectively (Table 1). Moreover, BET surface area changed from 1.63 to 507 m\({}^{2}\)/g, respectively (Table 1). This conclusion is agreement with the structural properties of the samples as listed in Table 1. \begin{table}
\begin{tabular}{c c c c c} \hline
**Sample ID** & **Density \({}^{\text{a}}\) (g/cm\({}^{3}\))** & **Pore Volume \({}^{\text{b}}\) (cm\({}^{3}\)/g)** & **BET Surface Area \({}^{\text{b}}\) (m\({}^{2}\)/g)** & **Average Pore Size \({}^{\text{b}}\) (nm)** \\ \hline S100 & 0.355 & 0.026 & 1.63 & 63.7 \\ S50 & 0.373 & 0.525 & 158 & 14.2 \\ S40 & 0.380 & 0.551 & 296 & 7.4 \\ S0 & 0.394 & 0.767 & 507 & 6.1 \\ \hline \end{tabular}  
* Density values were calculated from buoyancy experiments in helium. \({}^{\text{b}}\) These values are determined by using Micrometrics 2420 Surface Area and Porosity Analyzer.  
\end{table} 
Table 1: Structural properties of different mixed MWCNT/AC-RFA compositions. Figure 7: Isotherms of N\({}_{2}\) adsorption/desorption at \(-196\)\({}^{\circ}\)C onto different MWCNT/AC-RFA sample compositions; namely S100, S60, S50, S40 and S0. Solid circles refer to adsorption data and empty circles refer to desorption data. Figure 8 exposes the XRD patterns of different MWCNT/AC-RFA mixed sample compositions; namely S100, S60, S50, S40 and S0. It is noted that the peaks at 20 of 26.1\({}^{\circ}\), 42\({}^{\circ}\) and 54\({}^{\circ}\) are assigned, respectively, to the (002), (100) and (004) planes of the hexagonal graphite structure of the MWCNTs [37; 45]. It was observed that the fingerprint band of MWCNTs (20 = 26.1\({}^{\circ}\)) exposed a diminuendo trend when increasing amount of AC-RFA into the mixed sample composition. Furthermore, other two small peaks at 21.4\({}^{\circ}\) and 54\({}^{\circ}\) were noticed in the samples ranging from S100 to S40 and disappeared in S0. It could be said through outcome results that the sharp peak at 26.1\({}^{\circ}\) and broad peaks at 21.4\({}^{\circ}\) refer, respectively, to the relative crystallinity and relative amorpohicity regions into the samples. The characteristic peak of MWCNTs at 26.1\({}^{\circ}\) diminished gradually when increasing the quantity of AC-RFA into the composition. Figure 9a is a summary of FWHM of XRD peaks at 20 values of 26.1\({}^{\circ}\) and 21.4\({}^{\circ}\), which indicate to the relative crystalline section of MWCNTs and relative amorphous section of AC-RFA, correspondingly. It was observed that the FWHM of the band at 26.1\({}^{\circ}\) has a diminuendo trend, whereas that at 21.4\({}^{\circ}\) has a crescendo behavior with the increase in the AC-RFA ratio. Figure 9b represents the influence of the hybrid MWCNT/AC-RFA mixed sample composition on the XRD FWHM ratio (\(I_{26.1^{\circ}}/I_{21.4^{\circ}}\)).