Exploring the Structure and Chemistry of One-Dimensional and Two-Dimensional Lepidocrocite TiO₂ at Atomic Resolution

Low-dimensional materials are critical for enabling next-generation applications that are central to addressing critical global challenges. Titanium dioxide (TiO₂) nanostructures stand out because of their structural versatility and relevance to catalysis, energy conversion, and environmental remediation. Here, we employ a combination of advanced electron microscopy, spectroscopy, and first-principles theoretical calculations to investigate the structural and chemical properties of one- and two-dimensional lepidocrocite-type TiO₂. Special emphasis is placed on the one-dimensional material, which exhibits anisotropic growth, extending exclusively along a single-crystallographic direction. Our analysis suggests that this unusual growth behavior can be attributed to light-element impurities, such as carbon, that are incorporated during bottom-up synthesis. The results extend the understanding of these unexplored low-dimensional TiO₂ materials and offer fundamental insights into their structure and chemistry.