Ultrarapid degradation of perfluorooctanoic acid (PFOA) by 2D ultrathin Bi/BiOCl@g-C3N4 nanosheets: Facet engineering and Bi surface plasmon resonance

Perfluorooctanoic acid (PFOA) is currently regarded as a refractory pollutant. The development efficient degradation technologies remains a critical challenge owing to the strong stability of C-F bond. However, current photocatalytic approaches for PFOA degradation suffer from slow reaction kinetics. Herein, a series of ultrathin BiOCl@g-C 3 N 4 (BiCN) was prepared using a hydrothermal method, and their PFOA degradation performance was evaluated. The most effective photocatalyst (BiCN-2) achieved a 92.3% PFOA removal rate within 30 min (rate constant k  = 0.1059 min −1 ), with a corresponding defluorination efficiency of 24.8%. Specifically, the exposed (101) facets of BiOCl accelerate electron movement, whereas the BiOCl@g-C 3 N 4 heterojunction interface enhances the separation of photogenerated charges. Additionally, the metallic Bi nanoparticles acted as both electron bridges and sources of hot electrons via the surface plasmon resonance effect, further boosting the reaction. Superoxide radicals, photogenerated electrons, and photogenerated holes were identified as the main reactive species in the degradation reaction. Density functional theory was employed to determine the interaction mechanism between PFOA and the photocatalyst. This study provides insights into an efficient alternative for the photocatalytic degradation of PFOA.