“Intermediate template” assisted assembly growth of transition metal doped 2D porous boron nitride sheet as an efficient adsorbent for CO2 capture

Transition metal doped 2D h-BN as a promising CO 2 adsorbent has recently been recognized, but the key to obtaining high-yield BN nanomaterials is to develop a simple synthetic method for practical industrial applications. Based on DFT calculation results, we found that Fe, Ni, and Co doping can significantly reduce the adsorption energy of h-BN for CO 2 . Accordingly, in-situ Fe, Ni, and Co doping of 2D BN nanosheets was achieved by “intermediate template” assisted molten salt method with sodium tetraborate and melamine as raw materials. During the synthesis process, the melamine was first transformed into two-dimensional C 3 N 4 (“intermediate template”) through controlled heating. The two-dimensional C 3 N 4 then acted as templates and carbothermic reducing agents to guide and promote the formation of two-dimensional BN. The Fe, Ni, and Co doped 2D BN nanosheets were synthesized at the temperature of 900 °C with up to 76 wt% yields, 1.77 times that of bulk BN prepared at the same experimental condition. In addition, Fe doped h-BN displayed a relatively high porosity with a specific surface area of 260.67 m 2 ·g −1 and its optimal CO 2 adsorption capacity could reach 7.69 cm 3 ·g −1 at 25 °C under atmospheric pressure in this research.