摘要
The effective detection of trace methyl mercaptan(CH_(3)SH)with low power consumption is crucial for assessing air quality and facilitating non-invasive diagnosis of diseases such as periodontitis.Herein,we synthesized a ternary CeO_(2)-ZnO-Ag nanocomposite by a simple sol-gel one-step method,which shows the capability of monitoring ppb-level CH_(3)SH under room temperature.The incorporation of Ag significantly reduces the particle size and increases the ratio of Ce^(3+)as well as oxygen vacancy.Furthermore,Ag nanoparticles improve light utilization efficiency in CeO_(2)-ZnO composites in favor of the separation of photo-generated charge carriers.The sensor based on the nanocomposites with 2 mol%Ag exhibits an exceptional response of 1.21 towards 50 ppb CH3SH at room temperature under photoassisted excitation(395 nm).Moreover,it shows a stable detection even in an environment with 57.6% humidity and high selectivity towards CH_(3)SH gas.The gas sensing mechanism study indicates that the enhancement in perfo rmance is prima rily attributed to an increased number of oxygen vacancies and the spillover effect of Ag,ultimately leading to an augmented reaction rate of CH_(3)SH on the surface of the sensing material.This work demonstrates that the optimized CeO_(2)-ZnO-Ag nanocomposites hold great promise for highly selective and sensitive detection of trace CH_(3)SH gas under specific humidity conditions.
基金
Project supported by China Postdoctoral Science Foundation(2020M673172)
National Natural Science Foundation of China(61901401)。
