Amino-modified biochar-silica hybrid aerogels with ordered pore structure templated by cellulose nanocrystals for highly efficient and selective CO2 capture

Carbon dioxide (CO2) emissions from the combustion of fossil fuels are contributing to global climate change and ocean acidification, and the development of low-cost, highly efficient CO2 capture adsorbents for the reduction of CO2 concentrations is now a matter of urgency. Herein, we developed amine-modified biochar-silica hybrid aerogels template cellulose nanocrystals (CNCs) for CO2 capture. CNCs can self-assemble into an ordered lamellar structure and maintain their original structure after calcination in N2 atmosphere. At the same time, we chemically modified the hybrid aerogels with amines. The ordered pore structure and chemical modification effectively enhanced the CO2 adsorption capacity and rate of hybrid aerogels. The test showed that our material exhibited high adsorption properties of 2.81 mmol g−1 (0 °C, 1 bar). This work offers research ideas and methods for fabricating amine-modified biochar-silica hybrid aerogels for CO2 capture.