2D-Bi₂MoO₆/2D-g-C₃N₄ nanosheet heterojunction composite: synthesis and enhanced visible light photocatalytic mechanism

摘要： In this study, a novel 2D Bi2MoO6 nanosheet/2D g-C3N4 nanosheet heterojunction composite was fabricated through hydrothermal strategy. Afterwards, physicochemical properties of the composite were systematically detected by series of measurements. In addition, photocatalytic activity was evaluated by degradation of Rhodamine B, methylene blue, Amido black 10B and malachite green. Results showed that Bi2MoO6/g-C3N4 played higher photocatalytic efficiency than that of pristine Bi2MoO6 and g-C3N4 sample under visible irradiation. This phenomenon could be attributed to the combination of Bi2MoO6 and g-C3N4 as well as unique 2D/2D heterostructure. Also, the as-fabricated Bi2MoO6/g-C3N4 composite possessed higher surface area, narrower band gap energy, larger electron transport capability and longer charge carrier lifetime. Furthermore, the enhanced visible light driven photocatalytic mechanism was proposed and confirmed, which was mainly ascribed to the Z-scheme structure. That was, the photogenerated electrons (e-) in the CB of Bi2MoO6 and photogenerated holes (h+) in the VB of g-C3N4 would combine with each other quickly, so that the e- in the CB of g-C3N4 and h+ in the VB of Bi2MoO6 participated in reduction and oxidation reactions, respectively. Also, this composite exhibited superior physicochemical stability. Hence, it would be applied in advanced wastewater treatment.