Construction of SnNb2O6 nanosheet/g-C3N4 nanosheet two-dimensional heterostructures with improved photocatalytic activity: Synergistic effect and mechanism insight

•Novel SnNb2O6/g-C3N 2D/2D nanosheet heterostructures were synthesized.•SnNb2O6/g-C3N4 heterostructures have strong interfacial interaction.•The heterostructures showed enhanced visible-light photocatalytic activity.•The enhanced activity was mainly due to improved interfacial charge transfer.•The hole and superoxide radicals are the two main photoactive species.

In this study, novel SnNb2O6/g-C3N 2D/2D nanosheet heterostructures with strong interfacial interaction were successfully constructed by a facile two-step wet chemistry method. The SnNb2O6/g-C3N4 2D/2D heterostructures exhibit distinctly enhanced visible light photocatalytic performance toward the degradation of methylene blue (MB) as compared to pristine g-C3N4 and SnNb2O6, which can be attributed to the synergistic effect of 2D/2D heterostructures with strong interfacial interaction and abundant 2D coupling interfaces, facilitating efficient charge separation. The optimum photocatalytic activity of 30% SnNb2O6/g-C3N4 heterostructure for the degradation of MB was about 3.9 and 3.2 times higher than those of g-C3N4 and SnNb2O6. It was demonstrated that the photogenerated holes and superoxide radicals are the two main photoactive species toward photocatalytic degradation of MB over the SNO/CN heterostructures. This work may provide some inspiration for the fabrication of 2D/2D nanosheet heterostructures with efficient photocatalytic performance.

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