AlN/BP Heterostructure Photocatalyst for Water Splitting

In this letter, the structural, electronic, and optical properties of blue phosphorene (BP) and graphene-like aluminum nitride (AlN) nanocomposite are investigated by the first-principles method. Despite the indirect bandgap nature of the BP and AlN monolayers, AlN/BP heterostructure exhibits a direct bandgap characteristic in the most stable pattern. Moreover, we also find that the optically active states of the maximum valence and the minimum conduction bands are localized on opposite monolayers, leading to the electrons and holes spontaneously separated (type-II band alignment), which enhances the photocatalytic efficiency. Most interestingly, the AlN/BP heterobilayer exhibits enhanced optical properties in the visible and UV light zone, which is comparable or even superior to pristine BP - overall, the suitable direct gap and band edges positions, type-II band alignment, and fascinating visible and UV light adsorption, which enable AlN/BP heterostructure to have great potential applications in the field of solar energy conversion and photocatalytic water splitting.