Abstract:
The interactions between monolayer graphitic carbon nitride (g-C3N4) and conjugated polymer poly(9-
vinylcarbazole) (PVK) have been explored. We investigated the enhanced photocatalytic mechanisms for the
novel g-C3N4/PVK nanoheterojunction covering the state-of-the-art of DFT by performing rigorous DFT calcu lations combined with van der Waals corrections (GGA + vdW). The calculated band alignment between g-C3N4
monolayer and PVK monomer clearly reveals that the conduction band minimum and the valence band
maximum of g-C3N4 monolayer are higher than those of the conjugated polymer PVK. This predicted band
alignment ensures the photogenerated electrons easily migrate from the g-C3N4 monolayer to the PVK monomer,
and will lead to high hydrogen-evolution reaction activity. The charge transfer between g-C3N4 monolayer and
PVK results in a polarized field within the interface region, which will benefit the separation of photogenerated
carriers. The calculated density of electronic states, Lowdin charge transfer and charge density difference certify
that this proposed layered nanoheterojunction is an excellent light-harvesting semiconductor. These findings
indicate that the conjugated polymer PVK is a promising candidate as a non-noble metal co-catalyst for g-C3N4
photocatalysis. It also provides useful information for understanding the observed enhanced photocatalytic
mechanisms in experiments.
