Umek Polona, Dürrschnabel Michael, Molina-Luna Leopoldo, Škapin Srečo, Korošec Romana Cerc, Bittencourt Carla
Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia.
Karlsruhe Institute of Technology, P.O. Box 6980, 706049 Karlsruhe, Germany.
Molecules. 2023 Aug 3;28(15):5838. doi: 10.3390/molecules28155838.
CeO-TiO is an important mixed oxide due to its catalytic properties, particularly in heterogeneous photocatalysis. This study presents a straightforward method to obtain 1D TiO nanostructures decorated with CeO nanoparticles at the surface. As the precursor, we used HTiO nanoribbons prepared from sodium titanate nanoribbons by ion exchange. Two cerium sources with an oxidation state of +3 and +4 were used to obtain mixed oxides. HAADF-STEM mapping of the Ce-modified nanoribbons revealed a thin continuous layer at the surface of the HTiO nanoribbons, while Ce cerium ions intercalated partially between the titanate layers. The phase composition and morphology changes were monitored during calcination between 620 °C and 960 °C. Thermal treatment led to the formation of CeO nanoparticles on the surface of the TiO nanoribbons, whose size increased with the calcination temperature. The use of Ce raised the temperature required for converting HTiO to TiO-B by approximately 200 °C, and the temperature for the formation of anatase. For the Ce batch, the presence of cerium inhibited the conversion to rutile. Analysis of cerium oxidation states revealed the existence of both +4 and +3 in all calcined samples, regardless of the initial cerium oxidation state.
CeO-TiO由于其催化性能，特别是在多相光催化中的性能，是一种重要的混合氧化物。本研究提出了一种直接的方法来获得表面装饰有CeO纳米颗粒的一维TiO纳米结构。作为前驱体，我们使用了通过离子交换由钛酸钠纳米带制备的HTiO纳米带。使用两种氧化态为+3和+4的铈源来获得混合氧化物。对Ce改性纳米带的高角度环形暗场扫描透射电子显微镜（HAADF-STEM）成像显示，在HTiO纳米带表面有一层连续的薄层，而Ce铈离子部分插层在钛酸酯层之间。在620℃至960℃的煅烧过程中监测相组成和形态变化。热处理导致在TiO纳米带表面形成CeO纳米颗粒，其尺寸随煅烧温度增加。Ce的使用使将HTiO转化为TiO-B所需的温度提高了约200℃，以及锐钛矿形成的温度。对于Ce批次，铈的存在抑制了向金红石的转化。对铈氧化态的分析表明，所有煅烧样品中都存在+4和+3价铈，无论初始铈的氧化态如何。
