Progress in NASICON-based mixed-potential type gas sensors

The mixed-potential type gas sensors combining NASICON with oxide electrodes exhibit high sensing performance to typical pollution gases in the atmospheric environment in the intermediate temperature range, indicating a potential in practical application. This paper describes the state-of-the-art for the sensors based on the NASICON, including the current-type, the equilibrium-potential-type and mixed-potential-type. For improving the performance of sensors based on the NASICON and oxide electrodes, two main approaches have been utilized: the developing of new oxide electrode materials and the design of novel sensor structure for enhancing the sensing performance as well as the sensing mechanism involved in the mixed potential.