An Ultrahigh Performance Enzyme-Free Electrochemical H2O2 Sensor Based on Carbon Nanopores Encapsulated Ultrasmall Cobalt Oxide Nanoparticles

Small metal oxide nanoparticles (NPs) that possess abundant accessible active areas and optimal geometric/electronic structures show great promise in electrochemical detection of hydrogen peroxide (H2O2) but remain a synthetic challenge. Herein, a simple adsorption-annealing synthetic strategy is employed for ultrasmall Co3O4 NPs using the confinement of carbon nanopores in porous carbon (PC). The characterization results indicate that Co3O4 NPs with an ultrafine diameter of 3.01 nm are well distributed on PC (Co3O4/PC-H) with high density because of the carbon nanopore confinement of the support. The achieved Co3O4/PC-H can be used as an excellent electrocatalyst for H2O2 detection, with a high sensitivity of 332 mu A mM(-1) cm(-2), a low detection limit of 1.2 mu M, and an excellent linear detection ranges from 0.04 to 20 mM. This catalyst can also be employed for sensing H2O2 in real samples. The large specific surface area and unique morphology and structure of Co3O4/PC-H contribute to the high performance for H2O2 detection. Provided herein is a facile but efficient strategy for the synthesis of enzyme-free electrochemical H2O2 sensor for analytical applications.

Automated summary

A simple adsorption-annealing synthetic strategy was employed to prepare ultrasmall Co3O4 NPs using the confinement of carbon nanopores in porous carbon. The Co3O4/PC-H obtained exhibited excellent electrocatalytic performance for H2O2 detection, with high sensitivity, low detection limit, and excellent linear detection range. This represents a facile but efficient strategy for the synthesis of an enzyme-free electrochemical H2O2 sensor with high performance for analytical applications.