In situ dual-utilize of ZnCl2 for preparation of ZIF-8 functionalized biomass-based porous carbon for adsorption removal of volatile organic compounds

Abstract

In this study, ZnCl₂ was successfully dual-used for the chemical activation of biomass-based activated carbon (BAC) and ZIF-8 synthesis to prepare the functionalized porous carbon composite PC-Z/W. The findings indicated that the chemical activator ZnCl₂ be directly recycled for the synthesis of ZIF-8 on BAC. The ZIF-8 functionalization provided the PC-Z/W composites with a well-developed porous structure and rich N- and O-containing surface functional groups, which enabled the PC-Z/W to exhibit superior adsorption properties (large adsorption capacity, temp adaptability, and competitive adsorption with water) for low-concentration gaseous pollutants. The PC-Z/W(P1000) exhibited the best adsorption performance for toluene, with a saturation adsorption capacity (q_s) of 277 mg/g at 25 °C and retained 70 % of q_s (192 mg/g) at 80 °C. It also has exceptional adsorption capabilities for acetone (q_s = 170 mg/g) and ethyl acetate (q_s = 227 mg/g), enabling it to show superior multi-component adsorption behavior and effective competition with water. In addition to VOCs, PC-Z/W is also noteworthy for the adsorption of inorganic substances like SO₂ (203 mg/g) and CO₂ (4.65 mmol/g), greatly broadening its application prospects.