Trimetallic zeolitic imidazolate framework-derived hollow structure as a sensing material for nitrite electrochemical detection

A hollow structure is characterized by well-defined inner voids, high surface area, and numerous active sites, exhibiting great potential in electrochemical sensing. Herein, a trimetallic zeolitic imidazolate framework (ZnCoMn ZIF-67) was synthesized and then treated with dopamine (DA) to produce hollow ZnCoMn ZIF-67@DA (H-ZnCoMn ZIF-67@DA). Hollow Co, Mn, N-doped-porous carbons (H-CoMnN-PCs) were prepared through a pyrolysis treatment, and the resulting material retained the hollow structure of the precursor. The structural characteristics of the prepared material were evaluated through different techniques. Under optimized conditions, the nitrite sensor prepared using H-CoMnN-PCs exhibited two linear working ranges of 0.1–1500 and 1500–12000 μM, with a low detection limit of 0.097 μM. Moreover, the sensor featured high selectivity, stability, and reproducibility, making it a suitable candidate for various practical applications.