Z-scheme van der Waals heterostructure of BC6N/Blue-Phosphorene as a promising visible-light photocatalyst

Two-dimensional van der Waals heterostructures have had a great impact on designing efficient photocatalysts. Through first-principle calculations, we explore the prospect of BC₆N/blue-phosphorene heterostructure in metal-free photocatalysis. To investigate the photocatalytic ability and the underlying mechanism, we calculate its optoelectronic, thermodynamic, and charge migration properties. This indirect band-gap semiconductor has a gap of 1.6 eV and provides suitably aligned band-edges to simultaneously perform photocatalytic oxidation and reduction. Moreover, the internal electric field makes the photogenerated electrons follow the Z-scheme pathway, which ensures efficient electron–hole separation without compromising the thermodynamic drive for the catalytic reactions. Additionally, the red-shifted absorption spectra of the heterostructure promote high photon harvest in the visible range upon solar illumination. The synergy of improved charge separation and increased number of harvested photons would drastically boost the photocatalytic performance. These results establish BC₆N/blue-phosphorene as potential visible-light-driven metal-free photocatalysts that address diverse environmental challenges.