Bamboo and coconut shell based activated carbon: A Raman spectroscopic study

In this paper, we present a detailed report on Raman spectroscopic analysis of activated carbon (AC) samples obtained from two different biomass sources, namely, bamboo and coconut shell. The detailed analysis revealed that the local structure of the precursors was affected differently by the physical and chemical treatments prior to the preparation of AC. This leads to different structural features of the derived AC samples though processed under similar conditions. The influence of preparation methods and temperature on modifications in the D-, G-, and 2D-peak parameters of bamboo and coconut shell based AC (BAC and CSAC) such as peak positions, peak widths and peak intensity ratio were thoroughly described. We experimentally validate the stage-two of the three stage Ferrari-Robertson phenomenological model of amorphous carbon for these biomass derived AC. We also show that the observed anomalies in the peak parameters are consistent with the stage-two process combined with the networking properties of biomass derived AC. Physically activated BAC and chemically activated CSAC prepared at a temperature of 600 °C showed greater disorder (ID/IG) values of 1.37 and 1.22 in their AC structures, respectively. Further analysis of 2D-peak indicated the greater turbostratic disorder (quasi 2D-continuous random network) in BAC compared to CSAC.