Facile one-step deposition of Co3O4-MoS2 nanocomposites using a vacuum kinetic spray process for non-enzymatic H2O2 sensing

Co3O4-MoS2 nanocomposites (NCs) were deposited on titanium sheets at room temperature using a vacuum kinetic spray process and Co3O4 and MoS2 micro powders. Co3O4-MoS2 NCs/Ti electrodes were used as electrocatalysts for non-enzymatic detection of H2O2 in 0.1 M NaOH. X-ray photoelectron spectroscopy revealed an improvement in the synergy between various cobalt-based active sites and MoS2 species in all hybrid electrodes. Analysis of the amperometric response of H2O2 oxidation in 0.1 M NaOH revealed that titanium-modified electrodes with either nanostructured Co3O4 or Co3O4-MoS2 NCs exhibited a wide linear detection range of 20 mu M to 1mM. A gradual increase in the amount of Co3O4 in the modified electrodes led to a reduction in charge transfer resistance and the evolution of more electro-active sites at the working electrode surface, accompanied by an overall enhancement in detection sensitivity to a peak of 3000 mu A.mM(-1).cm(-2) at a Co3O4 content of 75 wt.%. Besides, the titanium modified electrodes with Co3O4-MoS2 NCs exhibited high selectivity for H2O2 oxidation in 0.1 M NaOH.