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

Abstract

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 (H 2 O 2 ) but remain a synthetic challenge. Herein, a simple adsorption-annealing synthetic strategy is employed for ultrasmall Co 3 O 4 NPs using the confinement of carbon nanopores in porous carbon (PC). The characterization results indicate that Co 3 O 4 NPs with an ultrafine diameter of 3.01 nm are well distributed on PC (Co 3 O 4 /PCÀ H) with high density because of the carbon nanopore confinement of the support. The achieved Co 3 O 4 /PCÀ H can be used as an excellent electrocatalyst for H 2 O 2 detection, with a high sensitivity of 332 μA mM À 1 cm À 2 , a low detection limit of 1.2 μM, and an excellent linear detection ranges from 0.04 to 20 mM. This catalyst can also be employed for sensing H 2 O 2 in real samples. The large specific surface area and unique morphology and structure of Co 3 O 4 /PCÀ H contribute to the high performance for H 2 O 2 detection. Provided herein is a facile but efficient strategy for the synthesis of enzyme-free electrochemical H 2 O 2 sensor for analytical applications.

Co‐based Catalysts for Selective H2O2Electroproduction via 2‐electron Oxygen Reduction Reaction

“…[88] Most of the previously reported Co 3 O 4 materials have been demonstrated as a class of highly efficient electrocatalysts for oxygen evolution reaction (OER), 4-electron ORR [89] and H 2 O 2 reduction reaction (H 2 O 2 RR). [90] Also, ZIF-67 derived Co 3 O 4 /rGO electrodes [90b] and ultrasmall Co 3 O 4 NPs [91] could be applied to the detection of H 2 O 2 . Importantly, Co 3 O 4 materials can also be used for converting O 2 to H 2 O 2 towards 2-electron ORR route through well-designed synthesis strategies.…”

An amphiphilic polyoxometalate–CNT nanohybrid as a highly efficient enzyme-free electrocatalyst for H2O2 sensing

“…19,20 Therefore, the development of new electrocatalysts towards efficient H 2 O 2 detection is highly needed. Recently, several non-enzymatic H 2 O 2 sensing materials have been reported such as CNT-Prussian blue, 21 Pt-graphene-CNT, 22 porous aromatic frameworks, 23 perovskites, 24 POM-based composites, 25 Co 3 O 4 -porous carbon, 26 the Au-Fe 3 O 4 hybrid, 27 and Pt-CD/IL-GO, 28 among others. 29,30 Although POMs show excellent catalytic properties, their sensing applications are limited by their low conductivities.…”