Valorization of Peanut Shell Biomass Into Sustainable Microporous Activated Carbons by H ₃ PO ₄ Activation for Enhanced CO ₂ Capture

ABSTRACT Here in this current research, sustainable activated carbons (ACs) were synthesized from peanut (PN) shells using an H 3 PO 4 activating agent in various percentages through a simple impregnation method, followed by carbonization at 750°C in N 2 flow. Furthermore, the resulting ACs was examined for their CO 2 uptake capacity. Among all the prepared ACs, activated carbon adsorbent PNC7 showed superior CO 2 uptake performance about 3.87 mmol/g at atmospheric pressure and 25°C conditions. Several factors contributed to the high CO 2 uptake, including a large micropore surface area (1195 m 2 /g), a large micropore volume (0.79 cm 3 /g), narrow pore size (0.75 nm), and more abundant basic oxygen functional groups. The significant high surface area was explained by I D /I G values and it was 1.31 for PNC7 activated carbon. In order to determine the textural properties of the ACs, a variety of characterization techniques were used, including x‐ray diffraction, Fourier‐transform infrared spectroscopy (FT‐IR), x‐ray photoelectron spectroscopy (XPS), N 2 adsorption and desorption, Field emission scanning electron microscopy (FE‐SEM), Raman, and CHNS elemental analysis. In addition, the adsorbent PNC7 demonstrated excellent recyclability during adsorption‐desorption up to ten consecutive cycles along with high CO 2 uptake. Furthermore, the dynamic CO 2 adsorption behavior was evaluated using kinetic models such as pseudo first, second, and avrami kinetic model.