Determining the Structure of One-Dimensional Lepidocrocite TiO₂ Nanoribbons with Atomic Resolution Scanning Transmission Electron Microscopy

One-dimensional (1D) materials are of interest because they offer high specific surface areas and host a variety of quantum size effects. Recently, Badr et al. reported on the synthesis of micron sized two-dimensional titanium carbo-oxide flakes composed of nanofilaments using a scalable process starting with inexpensive, abundant, nontoxic Ti-containing compounds like TiC and TiB₂ amongst many more. Band gap energy measurements suggest these nanofilaments are 1D in nature however, despite a variety of characterizations, questions remained concerning their chemical composition and atomic structures.

In this contribution we present an analysis of this 1D TiO₂ material using atomic resolution scanning transmission electron microscopy (STEM) as well as cryogenic electron energy loss spectroscopy (CryoEELS). We show that the building blocks of this material are 1D Lepidocrocite nanoribbons that align and order themselves in a variety of heterostructures. The interaction between the TiO₂ nanoribbons and surface functional groups, as well as their effects on the nanoribbon's ordering will be presented.