Metal-organic framework-derived leaf-like and stick-like Co3O4 for electrochemical sensing of H2O2

Developing electrochemical H2O2 sensors with high sensitivity and selectivity is highly desirable in the food industry. Low-dimensional transition metal oxides are promising in electrochemical sensing due to their attractive characteristics. In this study, leaf-like zeolitic imidazolate framework (ZIF-L) and stick-like zeolitic imidazolate framework (ZIF-S) were used to prepare leaf-shaped L-Co3O4 (L-Co3O4) and stick-shaped Co3O4 (S-Co3O4). The low-dimensional structure could shorten the electron transmission paths and expose more active sites. A series of characterizations were carried out to investigate the morphology and composition of these two materials. Further, the L-Co3O4 and S-Co3O4 were investigated for electrochemical H2O2 detection. The L-Co3O4 showed good electrocatalytic activity toward H2O2 in the ranges of 0.5–4500 and 4500–10000 μM with a detection limit of 0.47 μM. Moreover, the S-Co3O4 had good H2O2 detection performance in the ranges of 0.5–4500 and 4500–10000 μM with a detection limit of 0.33 μM. The constructed sensors also showed good anti-interference ability, reproducibility, stability, and applicability.