Insight into electro chemical and dielectric properties of flower shaped samarium embedded Y₂O₃@SeO₂ nanocomposites for H₂O₂ sensor applications

The rapid advancement in the sensor technology is critically influencing structure and morphology of the materials used. The researchers are taking keen interest in developing novel materials as sensors and actuators. In this work, Samarium doped Y₂O₃ @SeO₂ (Sm_x:Y₂O₃ @SeO₂, x = 1%, 8% and 12%) nanocomposites (NC) have been synthesized using microwave assisted method. The effect of Sm³⁺ substitution over Y₂O₃ @SeO₂ NC have been explored for morphological, structural, optical, sensor and dielectric properties. Crystal structure have been examined by X-ray diffraction (XRD) pattern and showed mixed phase of hexagonal/cubic structure. Morphology of the grains significantly affected by Sm³⁺ doping, resulted into flower/flake like microstructure. Redshift in optical absorption peak attributed to the enhancement of defect density with Sm³⁺ doping. The measurement of in depth morphology of the NC investigated using transmission electron microscopy (TEM), showed flower/flake shaped grains with size ∼ 16 nm. Frequency dependence real (ɛ') and imaginary parts (ɛ'') of dielectric constants at various temperatures ranging from 50 °C to 250 °C showed increase in (ɛ') as Sm³⁺ doping increases on Y₂O₃ @SeO₂ NC. The Sm_12%:Y₂O₃ @SeO₂ showed greater sensitivity towards hydrogen peroxide (H₂O₂) when exposed to volatile gases as compared with Y₂O₃ @SeO₂ NC. An exceptional limit of detection (LOD) of ∼0.68 μM has been realized. The non-enzymatic sensor was capable of detecting H₂O₂ with a wide linear range of 2–350 μM, linear regression of R² = 0.991 with a high sensitivity of 26 μA mM⁻¹. The present investigation can be used to develop sensors, optoelectronic devices and actuators.