Chen Xiaodan, Hosseini Seyed Naveed, van Huis Marijn A
Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
ACS Appl Nano Mater. 2022 Jan 28;5(1):1600-1606. doi: 10.1021/acsanm.1c04346. Epub 2022 Jan 7.
Anatase TiO nanocrystals (NCs) play a vital role in photocatalytic applications due to their high catalytic activity and in gas-sensing applications due to their high chemical sensitivity. Here, we report the transformation at elevated temperature of anatase nanorods (NRs) with a length of 25 nm into rock-salt TiO nanoparticles with an average size of 9.2 ± 2.1 nm investigated by means of in situ heating in the transmission electron microscope. The NRs were completely transformed to titanium monoxide NCs after heating to a temperature of 1200 °C. We also identified an intermediate stage in the temperature range of 950-1200 °C, during which not only the anatase and rock-salt phases were found but also the brookite phase. Understanding of the phase and morphology evolution at high temperatures is of essence to the functionality of the NRs in various applications, as discussed in this work. Moreover, the high-temperature transformation to titanium monoxide is of interest as rock-salt TiO (γ-TiO) is known to exhibit superconducting properties. We propose the heating-induced transformation as a physical route to synthesize TiO NCs of very small size.
锐钛矿型TiO纳米晶体（NCs）因其高催化活性在光催化应用中发挥着至关重要的作用，又因其高化学敏感性在气敏应用中发挥着重要作用。在此，我们报道了通过透射电子显微镜中的原位加热研究的，长度为25nm的锐钛矿纳米棒（NRs）在高温下转变为平均尺寸为9.2±2.1nm的岩盐型TiO纳米颗粒的过程。加热到1200℃后，NRs完全转变为一氧化钛NCs。我们还确定了在950 - 1200℃温度范围内的一个中间阶段，在此期间不仅发现了锐钛矿相和岩盐相，还发现了板钛矿相。如本工作所讨论的，了解高温下的相和形态演变对于NRs在各种应用中的功能至关重要。此外，由于已知岩盐型TiO（γ-TiO）具有超导特性，向一氧化钛的高温转变备受关注。我们提出加热诱导转变作为一种物理途径来合成非常小尺寸的TiO NCs。
