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Sulfonamides are commonly used antibiotics, but their residues in water bodies pose a potential threat to public health. In this study, we fabricated a 2D/2D composite heterojunction by integrating petal-like flake La2Ce2O7 with stacked slice BiOCl through an in-situ self-assembly method using hydrothermal synthesis. The physicochemical properties of the synthesized materials were systematically characterized. The photocatalytic performance of the composite photocatalyst was found to be superior to that of pure La2Ce2O7 and BiOCl, which can be attributed to the synergistic effect of both high carrier separation and mobility, which ultimately leads to the formation of a 2D/2D heterojunction interface contact between La2Ce2O7 and BiOCl. Notably, the construction of type II heterojunction helps electrons and holes to react on different semiconductors and facilitates the separation of electron–hole pairs. And the hydroxyl radicals and superoxide radicals were captured by electron spin resonance and the strong oxidizing nature of the radicals can effectively break the C–X bond, which is more favorable for the conversion degradation of sulfonamides. A possible photodegradation mechanism based on the catalyst of La2Ce2O7/BiOCl was hypothesized, providing a theoretical basis for preparing 2D/2D heterojunctions with a prominent photocatalytic activity. [ABSTRACT FROM AUTHOR]

A simple calcination approach was performed to synthesize layered K3Ti5NbO14/g-C3N4 (TNCN) composites, in which g-C3N4 was formed both within the interlayers and on the surface of N-K3Ti5NbO14. The photocatalytic activity of samples was evaluated by the visible-light photocatalytic degradation of rhodamine B (RhB). It was found that TNCN composite with a proper mass ratio of N-K3Ti5NbO14 to g-C3N4 exhibited the rapid rate of charge separation and high efficiency of light harvesting due to the synergetic effects of layered heterojunction and N doping, leading to an excellent photocatalytic activity. Especially, the in situ intercalated mono-layered g-C3N4 nanosheets can significantly increase the contact area between K3Ti5NbO14 layers and g-C3N4 nanosheets for efficient charge transfer across the interface, showing the greater effect on the enhanced photocatalytic activity. The active species trapping experiments and ESR measurements were carried out to evaluate the contribution of the active species in this photocatalytic degradation process. It was revealed that both superoxide radicals (·O2−) and holes (h+) are the main active species, while hydroxyl radicals (·OH) made a minor contribution to the photocatalytic degradation of RhB. [ABSTRACT FROM AUTHOR]