# Oxygen Vacancy Induced Structural Distortions in Black Titania -- A Unique Approach using Soft X-Ray EXAFS at the O K-Edge

## TL;DR

This study uses a novel soft X-ray EXAFS technique with a silicon drift detector to investigate how oxygen vacancies cause structural distortions in black titania, revealing their role in electronic property changes.

## Contribution

It introduces an innovative EXAFS method with a silicon drift detector to analyze bulk lattice distortions caused by oxygen vacancies in black titania.

## Key findings

- Oxygen vacancies induce specific lattice distortions in black titania.
- The new EXAFS technique effectively measures bulk interatomic distances.
- Structural distortions correlate with electronic mid-gap states.

## Abstract

Unknown changes in the crystalline order of regular TiO$_2$ result in the formation of black titania, which has garnered significant interest as a photocatalytic material due to the accompanying electronic changes. Herein, we determine the nature of the lattice distortion caused by an oxygen vacancy that in turn results in the formation of mid-band gap states found in previous studies of black titania. We introduce an innovative technique using a state-of-the-art silicon drift detector, which can be used in conjunction with extended x-ray absorption fine structure (EXAFS) to measure bulk interatomic distances. We illustrate how the energy dispersive nature of such a detector can allow us an unimpeded signal, indefinitely in energy space, thereby sidestepping the hurdles of more conventional EXAFS, which is often impeded by other absorption edges.