Layered Double Oxides for Sensing Reducing Volatile Organic Compounds: The Effect of Local Charge Region Modulation

Abstract

Multi-metal oxides with uniform distribution of various metal elements have potential for an enhanced gas-sensing response due to the strong heterogeneous and synergistic effects involved. In this study, three layered double oxides, labeled as CuCr-, ZnCr-, and ZnTi-LDOs, respectively, were prepared with corresponding LDHs (layered double hydroxides) as precursors and self-sacrificial templates. The elemental mapping confirms the uniform distribution of hetero-metal elements in whole LDOs. The CuCr-LDOs exhibits a much larger sensing response towards reducing VOCs at room temperature, which is 3.5 or 13.3 times that of ZnCr-or ZnTi-LDOs, respectively. The response differences are analyzed in terms of the local charge region modulation associated with heterojunction formation, and it is further demonstrated based on first-principles calculations and valence electron theory. The present work suggests a possible strategy for developing highly sensitive oxide-based gas sensors for VOCs detection.

Power‐Efficient and Highly Uniform BiFeO3‐Based Memristors Optimized with TiInSnO Electrode Interfacial Effect

“…As Figure 5e revealed, the TiInSnO thin film shows Fermi energy levels near the top of the valence band in the energy band, that is, the TiInSnO is a p-type semiconductor, indicating the film is in an electron deficient state with strong attraction to anions. [43,44] This means that a large number of oxygen ions are attracted on the TiInSnO and an oxygen-rich region is thus formed at the interface with BFO.…”