Twin HO-ZIF-67/NiCo-LDH with hollow structure as a novel coating for solid-phase microextraction of chlorophenols with boosting performance

Chlorophenols (CPs) are recognized persistent toxic pollutants (PTPs) that pose a significant risk to both the health of the environment and human beings due to their cancer-inducing properties and the presence of fertilityimpairing properties. For the sake of detect and adsorb CPs, in this paper, a twin hollow composite (HO-ZIF-67/ NiCo-LDH) derived from metal-organic frameworks (MOFs) and layered double hydroxides (NiCo-LDH) were designed and synthesized by simple combining the two dopants and carbonization, it had both high adsorption capacity and shortened adsorption equilibrium time. Using HO-ZIF-67/NiCo-LDH as a coating, a solid-phase microextraction (SPME) combining with high-performance liquid chromatography (HPLC) method was prepared to boosting extract CPs from complex matrices. Notably, with the optimal extraction conditions of orthogonal array design (OAD), the method provided a low detection limit (0.005---0.264 mu g center dot L-1), a wide linear range (0.018---1000.0 mu g center dot L-1), a favorable reproducibility, and an excellent performance in comparison with other materials as evaluated by thermodynamic and kinetic methods for adsorption performance (82.95---22.50mg g-1) and adsorption equilibrium time (20 min). This experiment provided a simple strategically sound approach for the synthesis of twin hollow MOFs adsorbents and explored the process of hollow structure formation. It realizes a new approach to adsorption and detection of organic pollutants by highlighting the advantages of two different materials and applying them in combination.