Fast-Response Ethanol Vapor Sensor Using Nickel-Doped Cerium Dioxide Nanoparticles with Enhanced Sensitivity
Abstract
In this paper, cerium dioxide (CeO2) nanomaterials doped with various nickel (Ni) contents (1%, 2%, 3%, and 7% in molar ratio) were synthesized using a facile coprecipitation method. The as-prepared materials were then utilized for the sensitive detection of volatile organic compounds (VOCs), specifically ethanol. Results show that Ni doping leads to a significant improvement in ethanol response compared to the pristine CeO2 sensor. Notably, the 2% Ni-doped CeO2 sensor exhibits the optimal ethanol sensing performance, achieving a response value of up to ~28 to 10 ppm ethanol at operating temperature of 230 oC. This response value is approximately 20 times higher than that of the pristine CeO2 sensor (~1.43). Additionally, the sensor exhibits fast response time (~16 s) and recovery time (~1 s). Moreover, the 2% Nickel (Ni)-doped CeO2 sensor has a response value of 3.02 for the low concentration of 0.5 ppm to ethanol vapor. This material also demonstrates great cycle stability, maintaining high stability over a 60-day testing period (RSD = 1.42%). The as-prepared Ni-doped CeO2 sensor exhibits high response value, rapid response time and excellent cycle stability, making it a promising candidate for practical applications in ethanol sensing.