Fabrication of highly sensitive acetone sensor based on sonochemically prepared as-grown Ag2O nanostructures

The sono-chemical synthesis of sliver oxide nanostructures was achieved by ultrasonic irradiation in aqueous alkaline solution (pH 8.33) at room conditions, where silver nitrate and urea were used as starting materials. The structures of as-grown Ag2O micro-flower (composed of nanosheets) were characterized using powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV/visible, Fourier transform infra-red (FT-IR). and Raman spectroscopy's etc. The chemical composition of Ag2O nanostructures was investigated by energy-dispersive X-ray spectrum (EDS). As-grown Ag2O nanosheets were applied for the chemical sensing using simple I-V technique in liquid phase system, where acetone was used as a target analyte. The analytical performances of acetone sensors with Ag2O using glassy carbon electrode (GCE) have good sensitivity, lower detection limit, and long-term stability in their electro-chemical responses. The calibration plot was linear (R = 0.9462) over the large dynamic concentration range (0.13 mu M to 0.67 M). The sensitivity was calculated to 1.6985 mu A cm(-2) mM(-1) with lower detection limit (0.11 mu M) based on a signal/noise ratio (3N/S) in short response time. Finally it was confirmed that the micro-flower morphologies (composed of nanosheets)and the optical features of silver oxide can be extended to a large range in un-doped semiconductor nanomaterials for proficient chemical sensor applications. (C) 2012 Elsevier B.V. All rights reserved.