Fig. 1 shows the N2 adsorption/desorption isotherms of the ACs derived from the raw/demineralized peat samples using different activation agents (H3PO4 and ZnCl2). The ACs derived from the demineralized peat consistently show a slightly higher N2 adsorption capacity than those from the raw peat, suggesting greater surface area and porosity in the ACs from the demineralized precursor.
As shown in the upper figure, H3PO4 ACs show isotherms similar to a type between types I, II and/or IV, indicating the presence of both micro-/mesopores. The isotherms for the H3PO4 ACs from both raw and demineralized precursors show a hysteresis loop between types of H3 and H4, indicative of slit-shaped pores and microporosity. As displayed in the bottom figure, the isotherms of the ZnCl2 AC-raw and ZnCl2 AC-dem samples differ from those for the H3PO4 ACs as discussed previously. The isotherms for the ZnCl2 ACs are typical of type II isotherm and H4 hysteresis loop, suggesting that the obtained ZnCl2 ACs are typical microporous materials.