Hard template synthesis of 2D porous Co₃O₄ nanosheets with graphene oxide for H₂O₂ sensing

Abstract

In this work, we used graphene oxide (GO) as a template that was removed by calcination to finally successfully prepare Co3O4 with 2D porous nanostructure. The results show that 2D porous structure Co3O4 nanosheets were only prepared at pH = 2. After electrochemical tests, the as-prepared Co3O4 nanosheets showed electrochemical properties that are highly suitable for H2O2 detection, such as high current response, short response time (less than 3 s), wide linear range (0.388–44.156 mM), low limit of detection (2.33 μM) and high sensitivity (0.0891 mA mM−1 cm−2). These excellent properties are mainly due to GO, as a 2D template, which connects Co3O4 nanoparticles to each other on a 2D plane, preventing the agglomeration of Co3O4 nanoparticles. The abundant pores between Co3O4 nanoparticles can greatly increase the reaction between the nanoparticles and H2O2 molecules.