The synthesis and characterization of high purity mixed microporous/mesoporous activated carbon from rice husk using chemical activation with NaOH and KOH

Abstract Activated carbon (AC) with high purity and surface area was synthesized from rice husk (RH) using alkali leaching at room temperature. Regular and pyridine FT-IR analysis had shown that the AC sample consists mainly of C C aromatic bonds and did not have Bronsted or Lewis acid sites respectively. In addition, the XRD patterns indicate that all AC samples were amorphous with slight micro-crystalline features due to the appearance of broad peaks at 2θ = 24° and 44° respectively. The maximum surface area obtained from the BET analysis was 2696 m2 g−1 for the KOH activated carbon at 850 °C with an impregnation ratio of 1:5 (RHC:KOH) under nitrogen flow. The SEM images also revealed the highly porous nature of the AC resulting in the high surface area. The TGA-DTG analysis of the AC samples showed that the samples are thermally stable up to 900 °C in nitrogen atmosphere.