2D/2D BiOIO₃/g-C₃N₄ S-scheme hybrid heterojunction with face-to-face interfacial contact for effective photocatalytic H₂ production and norfloxacin degradation

A two-dimensional (2D)/2D hybrid heterojunction with face-to-face interfacial assembly is a desirable dimensionality design with significant potential for various photocatalytic applications due to the large interfacial contact area, which facilitates charge migration and separation. Herein, we developed an efficient 2D/2D hybrid heterojunction consisting of BiOIO₃ nanoplates (BIO) and g-C₃N₄ nanosheets (CN) using a simple but effective in situ growth method for photocatalytic aqueous antibiotic degradation and H₂ generation. The face-to-face interfacial assembly of the BIO and CN components in the BIO/CN hybrid heterojunction was verified using electron microscopy. Remarkably, the BIO/CN hybrid heterojunction outperformed both the BIO and CN counterparts in terms of norfloxacin degradation and H₂ generation under simulated solar light irradiation. Moreover, the photocatalytic performance of the hybrid catalyst remained nearly unchanged throughout five consecutive test runs. The exceptional performance and stability of the hybrid catalyst are attributable to its extended optical absorption range, large interfacial contact area provided by the face-to-face assembly in the 2D/2D hybrid configuration, and enhanced photoexcited charge separation efficiency and redox power of the separated charges, which are supported by an efficient S-scheme charge transfer mechanism. This study illuminates the rational construction of novel 2D/2D S-scheme hybrid heterojunction photocatalysts with practical applications in environmental remediation and sustainable energy generation.