Preparation of CeVO4 with VO2 as precursor performing high selectivity and sensitivity to ammonia

Abstract

In this study, nano rod-like pure CeVO 4 and composite CeVO 4 are prepared from VO 2 as a precursor, adjusting the doping ratio of Ce. XPS results show that the V atoms on the surface of CeVO 4 are in the form of the V 5+ and V 3+ . V 3+ acts as the hanging key on the CeVO 4 surface and is used as an active site, conducive to the subsequent adsorption of ammonia and redox reactions. Thus, the free electrons absorbed by O 2 - return to the surface of CeVO 4 and improve its ammonia adsorption sensitivity. The prepared CeVO 4 ammonia sensor shows a high response (77,825%) and a faster recovery time (~2 s) at room temperature. To explore the effect of water molecules on the ammonia sensitivity of the sensor. Sensors are placed in salt solutions with different humidity. Results reveal a small resistance change in samples at low humidity, indicating that the ammonia gas could be monitored in real-time under low humidity conditions. • The phase and morphology of CeVO 4 are adjusted by Ce doping with VO 2 as a precursor. • V 3+ on surface of CeVO 4 as an active site raise the ammonia sensitivity of sensor. • The CeVO 4 sensor shows high and fast response to NH 3 with realtime test function.