Abstract This work emphasizes the effect of the physical activation using CO 2 and steam agents on the physicochemical properties of activated carbon produced from Dicranopteris linearis ( D. linearis ), a fern species widely distributed across tropic and subtropic ecoregions. The D. linearis -derived chars produced under pyrolysis at 400 °C for 1 h were activated in various CO 2 -steam proportions. As revealed by the IR and Raman spectra, the structure of the activated chars was heavily dependent on the relative proportion of CO 2 and steam. The total specific surface area (SSA) of the activated chars proportionally increased with the increase in steam proportion and was comparable to the values of commercial activated char products. Specifically, the activation under CO 2 − and steam-saturated conditions has correspondingly resulted in SSA increasing from 89 to 653 m 2 g −1 and from 89 to 1015 m 2 g −1 . Steam also enhanced the development of mesoporous structures of the D. linearis -derived char products, thereby extending their potential applications, particularly for industries that require high rigidity in the product such as pharmaceutical and cosmetic sectors.