*3.2. Raman Spectroscopy*

The Raman spectroscopy technique is commonly used to characterize carbon materials due to its ability to reveal the disordered structure of carbon molecules. The Raman spectrum of AC-700 ◦C and NAC-700 ◦C exhibits two peaks that corresponds to the Dband at (1360 cm−<sup>1</sup> ) and G-band at (1585 cm−<sup>1</sup> ) while the D-band represent the disorder in structure, and G-band represents vibration of carbon atoms, correspondingly as seen in (Figure 2). The intensity ratio of the D and G band is utilized to assess the level of graphitization in AC and NAC [23]. The intensity ratio (ID/IG) of AC and NAC are 0.9995 and 1.05, respectively. It indicates that the effect of N-doping guides the degree of the disorder and incorporation of heterogeneous atom (nitrogen) into the graphite layer therefore it can relate to, higher the intensity ratio the higher is the degree of disorder [27].

**Figure 2.** Raman spectroscopy of AC-700 ◦C and NAC-700 ◦C.
