Raman spectra of carbon samples exhibited the characteristic peaks

The FT-IR spectra of all carbons samples (Fig. 1) exhibited the typical bands of carbonyl groups (CO, CO, near 1700 cm−1) and characteristic peaks of incompletely carbonised materials, near 1580 cm−1 attributable (CC) to aromatic ring modes with varied absorbance. The structural difference of these proteinaceous BMS 193885 derived materials from the typical carbohydrate or sugar based catalysts were apparent from the presence of the nitrile band near ∼2360 cm−1 and a broad phosphate band between 1300 and 900 cm−1 due to incorporation of N and P into AC structures during carbonisation [29] and [30]. The sharper CO bands for hydrothermally prepared MACHT and carbon samples obtained from J cake (JAC, JACS) in comparisons to those obtained by activation of M and P cakes were in accord with their functionalized surface structures. While, the increased CO band intensity of MACH2SO4 as compared to MAC confirmed the formation of weak acid groups like COOH along with SO3H by oxidising effect of conc. H2SO4 on MAC surface and in good agreement with the trends found in literature (Fig. 1(b)), in contrast sulfonation by 4-BDS did not cause any such changes in CO band intensity (Fig. 1(a)) [4], [10] and [13]. Also, the success of sulfonation process and presence SO3H and PhSO3H groups on the surface of sulfonated carbons was confirmed by the emergence additional bands at 1110–1118 cm−1 and 1003–1018 cm−1 (SO stretching), 1171–1175 cm−1 and 1267–1270 cm−1 (stretching in SO3H) in the FT-IR spectra of these materials [9], [18], [20] and [25].