Er1-xYbxFeO3 (x = 0, 0.3, 0.7, 1) sensing materials were synthesized via sol-gel method and annealing. The obtained porous Er0.7Yb0.3FeO3 solid solution had the highest response value (Rg/Ra = 2.8) to 0.5 ppm butanone and the optimal selectivity compared with Er1-xYbxFeO3 (x = 0, 0.7, 1) sensing materials. The combination of Er3+ and Yb3+ rare-earth elements in A site of AFeO3, and proper proportion of Er to Yb make contribution to gas sensing properties of Er0.7Yb0.3FeO3 because they create the proper structure which has more electronic density of states near the Fermi level and the proper band-gap structure in Er0.7Yb0.3FeO3 according to the first-principle calculation results and UV–Vis diffusion spectra. Therefore, the better electronic structure of Er0.7Yb0.3FeO3 increases the amount of absorbed oxygen species on surface of materials, which is proved by the XPS results, and then enhances the response to target gas. In conclusion, Er0.7Yb0.3FeO3 has the great potential as gas sensing material used in detecting butanone and other hazardous gases.
