High performance NH3 sensor based on CeO2/In2O3 heterostructure for mutton preservation detection

In this work, a high performance NH3 sensor based on CeO2/In2O3 (CeIn) was synthesized by hydrothermal method. Experiment results depict that heterogeneous structure can efficiently enhance the performance of NH3 sensor based on In2O3 or CeO2 at room temperature (RT), which is due to more oxygen vacancies, free oxygen and hydroxy (-OH) groups on the surface of CeIn. In gas detection, the average response towards 1000 ppm NH3 is about 8628.89, three orders of magnitude higher than that of In2O3 or CeO2 sensor. Moreover, CeIn sensor has a fast response/recovery time of 1.8 s/1.5 s for 15 ppm NH3 and a minimum detection limit of 0.155 ppm, which can be used to monitor the freshness of mutton in different storage environments by detecting different concentrations of NH3 released during mutton deterioration. This work indicates the NH3 sensor based on CeIn has a potential application in meat freshness monitoring.