Synthesis, Characterization of Activated Carbon from Rice Husk Ash and Influence of NaOH Ratio on its Properties

Abstract

This study presents the synthesis and characterization of activated carbon (AC) derived from rice husk ash (RHA) using a chemical activation method that does not require high-temperature heating. RHA, obtained from burning rice husks as a fuel for industrial boilers, was subjected to silica extraction to form biochar (BC). BC is then activated with NaOH using an ultrasound machine and vacuum-dried to form activated carbon (AC). The influence of the mass ratio of NaOH to BC (mNaOH:mBC) on the specific properties of the activated carbon was systematically analyzed such as structure, porous morphology, and thermal behavior. The results show that the activated carbon exhibits an amorphous structure with a surface consisting of randomly distributed particles of several micrometers in size. Furthermore, the activated carbon possessed a porous and hollow structure with varying pore sizes. Notably, the maximum surface area of the activated carbon was achieved at a NaOH to BC activation ratio of 7:1, reaching 823,913 m2/g. These findings underscore the suitability of the synthesized activated carbon for applications as adsorbent materials in water or gas, suggesting its potential for environmental remediation purposes.