An amperometric ethanol sensor by using nickel modified carbon-rod electrode

An amperometric ethanol sensor was developed by using nickel modified carbo n-rod electrode in an alkaline electrolyte. The affecting factors of sensin g characteristics, such as HNO3 pretreatment, electrodeposition time and te mperature were explored. The results show that the electrodeposition time a nd electrodeposition temperature have positive effect on the sensing reacti on. The HNO3 pretreatment shows negative effect on both current response an d sensitivity. However, HNO3 pretreatment shows positive effect on the resp onse time. The best electrodeposition condition is recommended as following : 1 h deposition time, 65 degreesC electrodeposition temperature, 1.2 M NiS O4, 0.126 M NiCl2 and 0.647 M H3BO3, and -0.8 V set potential (versus Ag/Ag Cl with saturated KCl solution). The correlation of sensing response curren t (i(d)) and ethanol concentration (C-L) is i(d) = 13.20 (muA/ppm) C-L in t he range of 0-1000 ppm ethanol concentration. Additionally, the prepared el ectrode had ii s response time (90% response time), 13.20 muA/ppm sensitivi ty. (C) 2001 Elsevier Science B.V. All rights reserved.