Exploring the structural characteristics and adsorption capabilities of cost-effective N- doped activated carbon derived from waste biomass for CO2 adsorption

In this work, ACs were originated from two different bio-waste sources of Date and Jujube seeds (DS and JS). The influence of the precursor type as well as KOH chemical activator ratio on the structural properties and CO 2 adsorption performances of synthesized ACs were assessed. Impact of pre-treatment of raw material via functionalization with urea on the performance of prepared adsorbents was also evaluated. Functionalized DS-based AC possessed the highest surface area and largest micropore volume equal to 864 m 2 /g and 0.33 cm 3 /g, respectively. CO 2 adsorption behavior of ACs was experimentally evaluated via TGA at different adsorption temperatures of 25 and 50 °C and CO 2 concentrations of 10 and 90 vol% under atmospheric pressure. Based on the TGA results, functionalized and non-functionalized DS-prepared ACs with KOH: biochar weight ratio of 2:1, demonstrated great CO 2 capture capacity up to 1.3 and 1.2 mmol/g, respectively under realistic condition of 10 vol% CO 2 and 25 °C. The urea-nitrogenation and KOH-activation as economical and simple approaches sensitively assisted preparation of a novel and promising N-doped porous AC from bio-waste resources which can be exploited for superior CO 2 capture applications. • The adsorbents obtained from date (DS) and jujube (JS) seeds and activated with KOH. • DSK2 (KOH: biochar molar ratio of 2:1) presented the largest CO 2 uptake of 1.21 mmol/g. • DSK2 exhibited superior CO 2 adsorption stability in comparison to JSK2. • DS modified with 15 wt% urea and then activated with KOH (KOH: precursor = 2). • Urea-modified DSK2 exhibited an 8.26% more CO 2 uptake compared to DSK2.