Effect of varying ethanol and water compositions on the acetone sensing properties of WO₃ for application in diabetes mellitus monitoring

Abstract

Tungsten oxide based gas sensors have attracted a lot of attention in breath acetone analysis due to their potential in clinical diagnosis of diabetes. The major problem with this material in sensor application has been remarkable response to all gases but low selectivity to specific gases. Herein, we report the gas sensing performance of WO 3 materials which were synthesized by varying water and ethanol ratios using a facile solvothermal method for acetone detection. The gas sensing properties of as-prepared WO 3 were tested on acetone C 7 H 8 , NO 2 , NH 3 , H 2 S and CH 4 under relative humidity. X-ray diffraction patterns show that as-prepared WO 3 samples are mainly composed of monoclinic WO 3 , a phase having relatively high selectivity to acetone. The as-prepared WO 3 sensors produced using 51:49 ratio of water: ethanol show an increase in acetone response as the acetone concentration increases and a decrease in acetone response as the relative humidity increases. The sensor responded to a very low acetone concentration ranging from 0.5 to 4.5 ppm which is normally found in human breath. Furthermore, the sensor exhibited high sensitivity and selectivity to low ppm of acetone at 100°C. On contrary, the sensor showed significantly lower response to other gases tested.

Influence of Gd content on structural, electronic, thermoelectric, and optical properties of WO3

“…Thin films grown with chemical methods sometimes provide such noisy patterns. XRD pattern of pure WO 3 thin films showed two peaks at 2θ values 23.22°and 35.81°having Miller indices (100) and (110), respectively, those were reported in the literature as well [27,28]. In case of thin films, only one or few peaks appeared associated with prominent planes, unlike the bulk samples.…”

Controlled synthesis and structural modulation to boost intrinsic photocatalytic activity of BiVO4

“…This is because the dissociation of ethanol requires less energy ( (298 K) = −178 kJ mol −1 ) than that of water into H + and OH − ( (298 K) = −1693 kJ mol −1 ); therefore, ethanol + water produces substantial changes in the BiVO 4 phase and morphology. 50 Meanwhile, proton intercalation and dissolution process further assist the formation of the hyperbranched structure whereby growth along the [010] direction (branch) is strongly attacked by H + compared to the growth rate along the [100] direction (trunk), resulting in shortened branches. 51 Control experiments in the synthesis of BVO-SLR’24 suggest that HNO 3 had a significant impact on the transformation of nanodendrites (2 mL HNO 3 ) to multiple branched (4 mL HNO 3 ) and chromosome (6 mL HNO 3 )-like nanostructures (please see ESI† Fig.…”

UV activated single aligned TiO2 nanofiber embedded silver nanoparticles as room temperature ammonia gas sensor

“…The analysis of volatile compounds is an effective way to obtain appropriate information on the chemical constituents of the substances [1,2]. On this basis, one can analyze the volatile constituents of the human body collected through the skin, respiration, body fluids, etc, which contain useful information about one's illnesses [2][3][4]. Respiratory analysis has been extensively investigated and many diseases could be identified [5][6][7].…”