Porous Boron Nitride for Combined CO2 Capture and Photoreduction

Porous and amorphous materials are typically not employed for photocatalytic purposes as their high number of defects can lead to low charge mobility and favour bulk electron-hole recombination. Yet, with a disordered nature can come porosity, which in turns promotes catalyst/reactant interactions and fast charge transfer to reactants. Here, we demonstrate that moving from h-BN, a well-known crystalline insulator to amorphous BN, we create a semiconductor, which is able to photoreduce CO2 in a gas/solid phase, under both UV-vis and pure visible light, ambient conditions, without the need for cocatalysts. The material selectively produces CO and maintains its photocatalytic stability over several catalytic cycles. The performance of this un-optimised material is on par with that of TiO2, the benchmark in the field. Owing to the chemical and structural tuneablity of porous BN, these findings highlights the potential of porous BN-based structure for photocatalysis and particularly solar fuels production.