| 학회 | 한국재료학회 |
| 학술대회 | 2020년 가을 (11/18 ~ 11/20, 휘닉스 제주 섭지코지) |
| 권호 | 26권 1호 |
| 발표분야 | G. 나노/박막 재료 분과 |
| 제목 | Dependence of the different facets in TiO2 micro-sheets on gas sensing capability |
| 초록 | TiO2 based-materials including pristine TiO2, metal-assisted TiO2, organic-TiO2 composites, carbon-TiO2 composites and MOX-TiO2 composites have been studied as gas sensors for various gases. Enlarged specific surface area and improved surface characteristics have asigned them important roles for gas sensing applications. For many years, many reports have shown that the composited morphology based on TiO2 materials determines the response or sensitivity for a certain type of gas species, however, there is no research to understand their fundamental characteristics for a single pristine TiO2 nano/microstructure with different facet ratios and their reaction to various gas molecules In this work, anatase-TiO2 single crystals were synthesized by fluorine-mediated hydrothermal process which helps the formation of a specific (001) facet, allowing the ratio between the (101) and the (001) facets to vary. Individual TiO2 micro-sheets were measured for their sensing capabilities of different gas species, such as hydrogen and various volatile organic compounds (VOCs). The results show that the higher the ratio of (101) facet, the higher the responsivity to the gas molecules, because each of the (101) and (001) facets possess different sensitivities and gas sensing mechanisms during the reaction process with the gas molecules. In other words, the diverse coverage of ionosorobed oxygen molecules on different facets varies the electron depleted surface regions on the (101) and (001) facet that determine the reactivity between the target gas and the oxygen molecule. In the end, this understanding provides new insights to quantifying specific facet and sensing mechanism in metal oxide gas sensors. |
| 저자 | 김명진, 노소영, 김봉중 |
| 소속 | 광주과학기술원 |
| 키워드 | TiO2 microstructure; gas sensor; sensitivity |
