A solution to boost acetone sensing performance of perovskite oxides chemiresistors: In-situ derived p-p heterostructures

Overcoming the intrinsically inferior chemiresistive sensing properties of ABO3 perovskites remains a long-standing challenge. Herein, the in-situ derived ABO3-based heterostructures is proposed as promising sensitive materials for achieving high-performance chemiresistive sensing application. For verifying the feasibility, we design mesoporous p-p heterostructures composites of La2O3/LaFeO3. In virtue of the formation of in-situ derived p-p heterojunctions, realizing the tailoring of charge carrier concentrations and energy band structure. Besides, the presence of La2O3 with highly catalytic activity is helpful for improving gas sensing reactivity, and can generate large amount of lattice oxygen defects. Accordingly, the mesoporous La2O3/LaFeO3-based gas sensor operating at 200 °C exhibits high sensitivity, fast response and recovery speed (9 s/15 s vs. 100 ppm), outstanding selectivity and low detection limit (500 ppb), whereas the acetone sensing characteristic of LaFeO3 based sensor is comparatively poor. Our work provides a facile strategy to improve chemiresistive sensing performances of ABO3 perovskites.