Polypyrrole Microsphere Modified Porous UiO-66 for Electrochemical Nitrite Sensing

Abstract

Herein, A new nanocomposite material (PPy/UiO-66) composed of conductive polypyrrole microspheres(PPy) and UiO-66 was prepared by a simple in situ polymerization method and established a new method for detecting NO 2 − . The relationship between the morphology and size of the PPy/UiO-66 interface material and its response performance and electrocatalytic performance was studied. The results show that the polypyrrole microspheres are uniformly compounded on the outer surface of the metal organic framework (MOF), which improves the surface properties of the material and greatly improves the conductivity of the MOF material. The particle size of the composite material is about 200 nm, and the particle size of the polypyrrole microspheres is about 30 nm. Electrochemical performance studies have shown that the composite material has an extended linear response concentration range of 0.05–1055.5 μM for detecting NO 2 − , a detection limit of 0.037 μM (S/N = 3), and a sensitivity of 297.7μA mM−1 cm−2. The sensitivity of the sensor to detect nitrite is 2.5 times that of the polymer composite material PANI/SnO2/GCE; and it is an order of magnitude lower than the detection limit of the nitrite sensor based on MOF material. Therefore, the sensor can be used as a potential sensing material for the detection of nitrite.