BIF-20, a zeolite-like porous boron imidazolate framework with high density of exposed B-H bonding, is combined with graphitic carbon nitride (g-CN) nanosheets via a facile electrostatic self-assembly approach under room temperature, forming an elegant composite BIF-20@g-CN nanosheet. The as-constructed composite preferably captures CO and further photoreduces CO in high efficiency. The photogenerated excitations from the carbon nitride nanosheet can directionally migrate to B-H bonding, which effectively suppresses electron-hole pair recombination and thus greatly improves the photocatalytic ability. Compared to the g-CN nanosheet, the BIF-20@g-CN nanosheet composite displayed a much-enhanced photocatalytic CO reduction activity, which is equal to 9.7-fold enhancements in the CH evolution rate (15.524 μmol g h) and 9.85-fold improvements in CO generation rate (53.869 μmol g h). Density functional theory simulations further prove that the presence of B-H bonding in the composite is favorable for CO adhesion and activation in the reaction process. Thus, we believe that the implantation of functional active sites into the porous matrix provides important insights for preparation of a highly efficient photocatalyst.

No abstract

Reported here is a versatile method capable of generating pore space partition in zeolitic boron imidazolate frameworks (BIFs), which is based on the coexistence of presynthesized boron imidazolate complexes and charge balancing carboxylate ligands. Using this method, boron imidazolate complexes are used to form zeolitic nets, while the carboxylate serves to partition large channel spaces into multiple domains. The generality of this method is shown by two distinct boron imidazolate frameworks mimicking GIS (BIF-41) and ABW (BIF-42) zeotype topologies. BIF-41 shows high selectivity sorption of CO2 over N2.