Ethanol-sensing properties of SmCoO3/MOx (M=Zn, Fe, Sn, In) having a heterojunction in wet air

The ethanol sensitivity–temperature curves of SmCoO3/ZnO, In2O3 have two peaks under dry air. The ethanol sensitivity of SmCoO3/MOx, except for SmCoO3/Fe2O3, extremely decreased in wet air. For SmCoO3/ZnO, the sensitivity peak at around 623 K decreased with increasing humidity. For SmCoO3/Fe2O3, the sensitivity peak at 373 K disappeared and a new peak appeared at around 773 K in wet air. For SmCoO3/SnO2, the sensitivity decreased with increasing humidity. For SmCoO3/In2O3, the sensitivity disappeared in wet air.