Production and characterization of activated carbons from pumpkin seed shell by chemical activation with ZnCl2

In this study, an activated carbon with high surface area was prepared from pumpkin seed shell by chemical activation with ZnCl2. The effects of impregnation ratio (IR) and activation temperature on the pore structure of the activated carbon were investigated. The activation temperatures and IRs were in the range of 400–600°C and 1:1–4:1, respectively. The chemical and physical properties of the obtained activated carbons were determined. Elemental analysis was applied to determine the C, H, N, and O contents, and Fourier transform infrared spectrophotometry was used to analyze the functional groups. The surface area, pore volumes, pore size distribution, and average pore diameter of the activated carbons were characterized by N2 adsorption at 77 K using the Brunauer–Emmett–Teller (BET), t-plot, and density functional theory methods. The surface morphologies of the pumpkin seed shell and the activated carbon were investigated by scanning electron microscope. The highest BET surface area and total pore volume of the activated carbon were obtained as 1,564 m2/g and 0.965 cm3/g, respectively, at 500°C and with an IR of 3:1. According to the experimental results, pumpkin seed shell is a suitable raw material for activated carbon production.