Synergistic effect between p-n heterojunction and oxygen vacancies of Co3O4-C/Fe-MOF for highly sensitive detection of trace atrazine

Atrazine is a type of herbicide widely used in agricultural production, and trace atrazine would cause human hormone disorders and even lead to cancer and cancer-related diseases. There are still significant challenges in the highly sensitive detection of trace atrazine. Herein, a Co3O4-C/Fe-MOF with p-n heterojunction and oxygen vacancies was theoretically predicted, and it had potential interactions with atrazine. Leaf-shaped Co3O4-C/Fe-MOF with p-n heterojunction and oxygen vacancies was in-suit constructed on the surface of foam nickel by self-assembly strategy. The electrochemical detection results showed that the Co3O4-C/Fe-MOF electrochemical sensor achieved ultra-low detection concentration (0.06 pM) and ultra-high detection sensitivity (60.32 μA/pMcm2) within an ultra-wide concentration range (1 pM-5 mM). The Co3O4-C/Fe-MOF electrochemical sensor was successfully applied for the detection of atrazine in real samples. In addition, theoretical calculations and experimental analysis systematically reveal the detection mechanism. The rich oxygen vacancies enhanced the adsorption of atrazine, and the p-n heterojunctions promoted electronic transitions to the material surface and react quickly with atrazine. The synergistic effect between p-n heterojunctions and oxygen vacancies promoted the electrochemical reaction kinetics of atrazine. This study provides a new strategy for designing active composite materials to achieve highly sensitive detection of harmful small molecules.