Hierarchical self-assembly structured Sm2O3 nanoparticles were prepared by a simple and cost effective hydrothermal method and subsequent annealing at 〖800〗^° C in air. The size, shape and phase composition of the structures synthesized by changing the hydrothermal processing time were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-Raman and photoluminescence (PL) analysis. Upon varying the timing of hydrothermal process (from 24 to 36 h) SEM analysis highlighted differences in the aggregation and coalescence of particles. XRD patterns revealed their crystalline nature while from Raman active modes the C-type structure of cubic Sm2O3 was confirmed. Sensor performances of the synthesized Sm2O3 nanostructures have been investigated for the monitoring of two important volatile organic compounds (VOCs) such as ethanol and acetone. The sensitivity, selectivity and response repeatability of the fabricated conductometric sensors were reported for the first time. Results demonstrate that Sm2O3 nanoparticles are effective in the monitoring of low concentration of both acetone and ethanol in air.
