The use of CeO2-modified Pt/C catalyst inks for the construction of high-performance enzyme-free H2O2 sensors

Abstract

In this work, the development of novel enzyme-free electrochemical hydrogen peroxide (H2O2) sensors with high sensitivity and wide linear range is described. The electrochemical sensors were constructed by the physical modification of commercial Pt/C catalysts with CeO2 metal oxide nanoparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM), N2-adsorption, and Raman spectroscopy methods were used to characterize the metal oxide nanoparticles. The CeO2 particles showed fluorite-type structure with the average crystalline size of 13.8nm. Furthermore, the Raman spectroscopy results indicated the presence of high degree of oxygen defects indicating the high redox property of the nanoparticles. The physical surface area of the metal oxide nanoparticles was determined to be 68.8m2g−1. The catalyst inks were prepared by mixing commercial Pt/C and CeO2 nanoparticles with different weight ratios. The analytical performance of the sensors was studied using cyclic voltammetry (CV) and chronoamperometry (CA) methods. The results revealed that the introduction of CeO2 nanoparticles into the catalyst layer improved the sensor performance significantly compared to Pt/C sensors. A high sensitivity of 185.4±6.5μAmM−1cm−2 was obtained from CeO2-modified sensors in a wide linear range of 0.01–30mM. Depending on the obtained results it can be suggested that the novel sensor design holds a great promise for the construction of electrochemical sensors with high sensitivity, selectivity, and wide working window.