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

An amperometric ethanol sensor was developed by using nickel modified carbon-rod electrode in an alkaline electrolyte. The affecting factors of sensing characteristics, such as HNO3 pretreatment, electrodeposition time and temperature were explored. The results show that the electrodeposition time and electrodeposition temperature have positive effect on the sensing reaction. The HNO3 pretreatment shows negative effect on both current response and sensitivity. However, HNO3 pretreatment shows positive effect on the response time. The best electrodeposition condition is recommended as following: 1 h deposition time, 65°C electrodeposition temperature, 1.2 M NiSO4, 0.126 M NiCl2 and 0.647 M H3BO3, and −0.8 V set potential (versus Ag/AgCl with saturated KCl solution). The correlation of sensing response current (id) and ethanol concentration (CL) is id=13.20 (μA/ppm) CL in the range of 0–1000 ppm ethanol concentration. Additionally, the prepared electrode had 11 s response time (90% response time), 13.20 μA/ppm sensitivity.