Twist angle-driven photoreduction of carbon dioxide on bilayer black phosphorus – A first-principles study

Abstract

Utilizing first principles calculations, the product selectivity in photocatalytic CO2 reduction was modulated by manipulating the twisted angle in bilayer black phosphorus. Four twisted angles, 0° (AA stacking), 15.40°, 19.00° and 24.66°, were constructed. Comprehensive investigations revealed enhanced carrier mobility and lifetime, especially at a 24.66° twist. Furthermore, an in-depth analysis of the CO2 reduction processes in these four systems was undertaken. Our simulations indicate that in the AA stacking, the photocatalytic CO2 reduction yields multiple products, including HCHO, CH3OH, and CH4, demonstrating limited product selectivity. However, when the surface is twisted at 15.40°, 19.00°, or 24.66°, the sole product is CH4. Remarkably, the 24.66° configuration exhibits the lowest energy barrier for the rate-determining step, measuring just 1.29 eV. These observations suggest that by carefully adjusting the twisted angle in bilayer black phosphorus, we can significantly improve both the activity and selectivity of CO2 photoreduction.