Effect of Particle Size on the Photocatalytic Activity and Sensing Properties of CeO2 Nanoparticles

Cerium oxide (CeO2 1) nanoparticles (NP) have been synthesized hydrothermally in the presence of urea and studied the effect of particle size on the chemical sensing and photo-catalytic properties of CeO2. CeO2 1 was described by field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), Raman spectrum, Fourier transform infrared spectroscopy (FTIR), and UV-visible absorption spectrum which divulged that the prepared product is well crystalline cubic phase optically active nanoparticles. SEM images of CeO2 1 illustrated that the synthesized product is composed of cumulative form of highly crytallinity spherical shape nanoparticles with an average diameter of ~ 12 ± 10 nm. Additionally, CeO2 1 was exploited as redox mediator for the development of ethanol chemi-sensor. The fabricated chemical sensor exhibited an excellent performance for electrocatalytic oxidization of ethanol by exhibiting higher sensitivity (1.192 μA.cm-2.M-1) and lower limit of detection (9.7 μM) with the linear dynamic range of 17.0 μM ~ 1.7 M. Moreover, by applying to organic pollutant, CeO2 1 degraded almost 50% of acridine orange in short time. By comparing with 2, CeO2 1 showed lower particle size, lower limit of detection and higher sensitivity toward ethanol sensing and high photo-catalytic activity for degradation of acridine orange. It is concluded that reduction in the particle size enhances the active surface area of the CeO2 which results in increase of chemical sensing and photo-catalytic properties of CeO2.