Pore structure regulation and carbon dioxide adsorption capacity improvement on porous BN fibers: Effects of high-temperature treatments in gaseous ambient

Abstract Recently, capture and storage of carbon dioxide (CO 2 ) has been an effective strategy to address global warming caused by excess CO 2 . Porous boron nitride (BN) with tunable porosity, excellent chemical stability and thermal stability have been considered as promising materials for CO 2 adsorption. Here, porous BN fibers with high specific surface area have been used as promising adsorbent for CO 2 capture. The effects of high-temperature treatments in different gaseous ambient on the microstructure evolution and CO 2 adsorption capacity of porous BN fibers are studied in detail. Interestingly, the porous BN fibers after high-temperature post-treatment in NH 3 gas show enhanced CO 2 adsorption capacity, as compared with pristine porous BN and nearly three times more than porous BN nanosheets reported before. The NH 3 -treatment can effectively restrain the damage of pore structure caused by high-temperature annealing, especially micropores. Moreover, in the NH 3 -treatment process, the impurities (B-O) of porous BN fibers can react with NH 3 to form B-N-H, which is the root cause of the enhancement of CO 2 adsorption capacity of porous BN fibers.