Three-dimensional Co3O4@MWNTs nanocomposite with enhanced electrochemical performance for nonenzymatic glucose biosensors and biofuel cells

Three-dimensional nanoarchitectures of Co 3 O 4 @multi-walled carbon nanotubes (Co 3 O 4 @MWNTs) were synthesized via a one-step process with hydrothermal growth of Co 3 O 4 nanoparticles onto MWNTs. The structure and morphology of the Co 3 O 4 @MWNTs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, scanning electron microscopy and transmission electron microscopy. The electrocatalytic mechanism of the Co 3 O 4 @MWNTs was studied by X-ray photoelectron spectroscopy and cyclic voltammetry. Co 3 O 4 @MWNTs exhibited high electrocatalytic activity towards glucose oxidation in alkaline medium and could be used in nonenzymatic electrochemical devices for glucose oxidation. The open circuit voltage of the nonenzymatic glucose/O 2 fuel cell was 0.68 V, with a maximum power density of 0.22 mW cm −2 at 0.30 V. The excellent electrochemical properties, low cost, and facile preparation of Co 3 O 4 @MWNTs demonstrate the potential of strongly coupled oxide/nanocarbon hybrid as effective electrocatalyst in glucose fuel cells and biosensors.