Activated carbon (AC) can be extracted from several agriculture residues which are basically carbon-rich materials. The objective of this research was the utilization of annual agriculture waste (cotton stalks) through the pyrolysis process to obtain a valuable adsorbent (activated carbon). The parameters used to evaluate the characteristics of FeCl3 activated carbon was, Fourier Transform Infrared Spectra (FTIR) technique which shows several peaks at 877 cm-1, 1156 cm-1, 1557 cm-1, 1568 cm-1, 1683 cm-1, 1695 cm-1, 1916 cm-1, 1991 cm-1, 2112 cm-1, and 2358 cm-1 and these all peaks identify the presence of various functional groups on the surface of the FeCl3-Based AC. In addition, a honeycomb structure of pores distribution was analyzed through Scanning Electron Microscopy (SEM) images and X-ray diffractometry (XRD) identified continues spectrum, which is the evidence for the thermo-change in the
crystalline structure of the FeCl3-Based AC. Furthermore, Iodine adsorption and Methylene blue adsorption were also carried out to measure the number of macro and micro pores with the values of 224 mg/gm and 156.25 mg/gm respectively. The moisture content of FeCl3-based AC
was also carried out because of the agricultural residue used to acquire charcoal and the result was 5.4%. This study revealed that the FeCl3-Based AC produce from cotton stalk is an easily
available and inexpensive adsorbent for the application in liquid and gaseous phases with advantageous surface adsorption properties.