The effect of chemical activators on the properties of activated carbon from sago waste was conducted in this study by using ZnCl2, H3PO4, KOH, and KMnO4 chemical solutions. The carbonized sago waste was added to each chemical solution, boiled at 85 °C for 4 h, and heated at 600 °C for 3 h. The porosity, microstructural, proximate, and surface chemistry analyses were carried out using nitrogen adsorption with employing the Brunauer Emmett Teller (BET) method and the Barret-Joyner-Halenda (BJH) calculation, scanning electron microscopy by using energy dispersive spectroscopy, X-ray diffractometer, simultaneous thermogravimetric analysis system, and the Fourier-transform infrared spectroscopy. The results showed that the activated carbon prepared using ZnCl2 acid had the highest specific surface area of 546.61 m2/g, while the KOH activating agent surpassed other chemicals in terms of a refined structure and morphology, with the lowest ash content of 10.90%. The surface chemistry study revealed that ZnCl2 and KOH activated carbon showed phenol and carboxylate groups. Hence, ZnCl2 acid was suggested as activating agents for micropore carbon, while KOH was favorable to producing a mesopore-activated carbon from sago waste.

Previous researches have shown that activated carbon could be made from various raw materials which contain lignocellulose. The aims of this research were to synthesis and characterize the activated carbon obtained from lignocellulose contained in sago waste. The synthesis was conducted through multiple stages of dehydration, carbonization, silica extraction with NaOH, activation by ZnCl2 10%, and surface modification using HNO3 65%, successively. From X-ray fluorescence, it was confirmed that treatment with NaOH removed practically all silica content from the sample with only 1 wt% left. The X-ray diffraction patterns showed that the samples have amorphous structures before the modification and started to form exfoliated graphite crystals, as shown by the peaks at 2θ 30.27° and 35.10°. The significant result was obtained from the series of processes of carbonization, extraction, activation, and modification using 1.5 mL of HNO3 (CEA 1.5), which produced nanoporous particles with regular homogeneous shapes in the range of 200 nm in size as shown by scanning electron images. Finally, the infrared spectra from activated and modified samples confirmed that the oxygen-containing groups had increased.