In-situ exfoliation of graphitic carbon nitride with metal-organic framework via a sonication-assisted approach for dispersive solid-phase extraction of perfluorinated compounds in drinking water samples.

Monitoring the levels of perfluorinated compounds (PFCs) in the environment is of vital importance, owing to their sustained environmental presence, extensive distribution, and associated health risks. The development of cost-effective and efficient sorbents for the establishment of sensitive analytical methods is critical for achieving trace-level detection. In this study, a graphitic carbon nitride (g-CN)-based sorbent is synthesized by a facile sonication-assisted method exfoliated by zeolitic imidazolate framework-67 (ZIF-67) in situ. The novel ZIF-67/g-CN composites were systematically characterized by transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and N adsorption-desorption analysis, exhibiting good dispersity and a large surface area. Moreover, molecular dynamics simulations indicated that g-CN structures can be effectively exfoliated by the introduced ZIF-67 molecules. The hybrid material was successfully utilized as a dispersive solid-phase extraction sorbent, and the extraction factors were systematically optimized by response surface methodology. Under optimal conditions, the synthesized sorbent exhibited desirable linear correlations (R > 0.99), a low detection limit (0.3-2 ng L), and good repeatability (relative standard deviation <15%, n = 6). The developed method was applied for the analysis of natural and spiked water samples. The study demonstrated that the ZIF-67/g-CN composites are promising materials for pollutant adsorption from drinking water samples.