Christiansen Troels Lindahl, Bøjesen Espen D, Juelsholt Mikkel, Etheridge Joanne, Jensen Kirsten M Ø
Department of Chemistry and Nanoscience Center , University of Copenhagen , 2100 Copenhagen Ø , Denmark.
ACS Nano. 2019 Aug 27;13(8):8725-8735. doi: 10.1021/acsnano.9b01367. Epub 2019 Aug 5.
Nanosizing of metal oxide particles is a common strategy for improving materials properties; however, small particles often take structures different from the bulk material. MoO nanoparticles show a structure that is distinct from the bulk distorted rutile structure and which has not yet been determined. Here, we present a model for nanostructured MoO obtained through detailed atomic pair distribution function analysis combined with high-resolution electron microscopy. Defects occur in the arrangement of [MoO] octahedra, in both large (40-100 nm) nanoparticles, where the overall distorted rutile structure is preserved, and in small nanoparticles (<5 nm), where a new nanostructure is formed. The study provides a piece in the puzzle of understanding the structure/properties relationship of molybdenum oxides and further our understanding of the origin of structural changes taking place upon nanosizing in oxide materials.
金属氧化物颗粒的纳米化是改善材料性能的常用策略；然而，小颗粒的结构往往与块状材料不同。MoO纳米颗粒呈现出一种不同于块状畸变金红石结构的结构，且该结构尚未确定。在此，我们通过详细的原子对分布函数分析结合高分辨率电子显微镜，提出了一种纳米结构MoO的模型。在大尺寸（40 - 100纳米）的纳米颗粒中，[MoO]八面体的排列出现缺陷，此时整体畸变的金红石结构得以保留；而在小尺寸（<5纳米）的纳米颗粒中，形成了一种新的纳米结构。该研究为理解钼氧化物的结构/性能关系拼图增添了一块内容，并进一步加深了我们对氧化物材料纳米化时结构变化起源的理解。
