Excellent photocatalytic activity of MoO₃-adorned g-C₃N₄ systems: Construction of S-scheme heterojunction

To alleviate harmful pollutants in water, photocatalytic technology, which offers green degradation of pollutants, is being used. The g-C₃N₄ is a metal-free organic polymer semiconductor photocatalyst widely used in photocatalysis. However, some drawbacks have limited its practical application. Thus, constructing of semiconductor heterojunction with appropriate band structure to improve photocatalysis activity for g-C₃N₄is an effective and common means to overcome the drawbacks. Therefore, in this study, MoO₃/g-C₃N₄ (MoCN) was prepared via the one-step calcination method. The photocatalytic performance of the composite was evaluated via photocatalytic degradation of rhodamine B (RhB) and the data revealed that the 3MoCN composite semiconductor greatly enhanced the activity (about 6.3 times) of pure g-C₃N₄ toward the degradation of RhB. Meanwhile, the free radical masking experiments suggested ^[rad]O₂⁻ as the major oxidizing species in the MoCN system. The specific area of the composite system of MoCN was 3.7-fold higher than that of pure g-C₃N₄. Furthermore, the photoelectric properties tests and DFT demonstrated improved photoactivity of MoO₃/g-C₃N₄ due to the movement of Fermi levels and built-in electric field close to the S-scheme heterojunction interface. Our work demonstrated a simple strategy to prepare efficient photocatalysts for environmental remediation.