Mulberry-like Zn-MOF/ZnS heterojunction constructed for high-sensitivity electrochemical simultaneous determination of naphthol isomers

In this work, we develop a new type of Zn-based electrode material, i.e., mulberry-shaped nanostructured zinc metal–organic frame/zinc sulfide (Zn-MOF/ZnS) heterojunction, which was synthesized via a green and convenient one-pot solvothermal method with common zinc salts as the metal precursor, 1,3,5-benzenetricarboxylic acid (H 3 BTC) as the organic ligand, and thioacetamide (TAA) as sulfur source. The porous structure of zinc metal–organic frame (Zn-MOF) can effectively adsorb and enrich naphthol molecules, accelerating material transport. Meanwhile, the integration of Zn-MOF with zinc sulfide (ZnS) to form the heterojunction interface can promote rapid electron transfer and improve the efficiency of electrocatalytic reactions. When used for electrochemical detection of naphthol isomers in water, the sensing performance of the resultant Zn-MOF/ZnS electrode is significantly improved in comparison with monolithic Zn-MOF and ZnS electrodes. The sensor achieves a detection linear range of 0.4–70 µM, with low detection limits of 30 nM for 1-naphthol (1-NAP) and 10 nM for 2-naphthol (2-NAP), respectively. In addition, the sensor has acceptable anti-interference ability, repeatability, and long-term stability, which can be used for the actual sensing of naphthol isomers in environmental water. This study provides new ideas and references for the development of high-performance electrode material for on-site monitoring of pollutants in water quality. Graphical