Optical and electro-catalytic studies of nanostructured thulium oxide for vitamin C detection

• Nanostructured thulium oxide has been prepared using the hydrothermal process.
• Thulium oxide exhibits excellent electrochemical response towards ascorbic acid.
• Thulium oxide is interesting electro-optical material.
• Rare earth metal oxide offers potential application biosensing and optoelectronics.

In this report, the nanostructured thulium oxide (Tm2O3) has been prepared using the hydrothermal process without using any template and further heat treatment. The crystalline structure and morphology of prepared sample have been determined by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopic techniques. The optical properties of prepared sample have been examined by ultra-violet (UV–Vis), photoluminescence (PL), Raman and X-ray photoelectron spectroscopy (XPS) studies. Furthermore, Tm2O3 nanoparticles have been electrophoretically deposited (EPD) onto indium–tin–oxide (ITO) glass substrate and utilized for electro-oxidation of ascorbic acid (AA). The electro-catalytic behavior of Tm2O3/ITO and bare ITO electrodes for AA electro-oxidation has been studied by cyclic voltammetry. Catalytic oxidation peak current shows a linear dependence on the AA concentration and a linear calibration curve is obtained in the concentration range of 0.2–8 mM of AA. The obtained results indicate that the nanostructured Tm2O3 based electrode offers an efficient strategy and a new promising platform for application of the rare earth metal oxide material in electrochemistry and bioelectronics.