Enhanced photocatalytic activity of a hydrogen bond-assisted 2D/2D Z-scheme SnNb2O6/Bi2WO6 system: Highly efficient separation of photoinduced carriers

2D/2D materials have attracted extensive attention in the field of photocatalysis due to their large contact surfaces and short charge transfer distances. However, 2D/2D heterojunction materials, especially those that connect different materials together using strong chemical bonds, are still challenging to prepare. Herein, a novel hydrogen bond-assisted 2D/2D Z-scheme SnNb 2 O 6 /Bi 2 WO 6 system was successfully prepared using a facile hydrothermal method . The 2D/2D Z-scheme system increases the accessible area for charges and constructs interfacial electric fields, thereby reducing the barriers for electron transport and enhancing the photocatalytic activity . In addition, the electronic coupling of the surface hydrogen bonds can further enhance the interfacial electric fields, which offers a new route for lowering the interfacial potential barrier of the system. As expected, the hydrogen bond-assisted 2D/2D Z-scheme SnNb 2 O 6 /Bi 2 WO 6 system results in an outstanding improvement of the norfloxacin (NOR) photodegradation efficiency, and the degradation rate constant (4.06 × 10 −2  min −1 ) is 9 and 2 times higher than those of SnNb 2 O 6 (4.33 × 10 −3  min −1 ), and Bi 2 WO 6 (1.70 × 10 −2  min −1 ), respectively. Simultaneously, three differently degradation pathways for the degradation of NOR were proposed based on the degradation products that were identified. Finally, a fast charge transfer mechanism of the hydrogen bonds that are connected to the 2D/2D Z-scheme SnNb 2 O 6 /Bi 2 WO 6 system is proposed, which is based on the ESR analysis and the DFT calculations.