Abstract
The precise control of electronic structure in nitrogen-doped titanium dioxide (N-TiO2) is crucial for optimizing its optoelectronic performance. In this study, N-TiO2 films were prepared via an in-situ hydrothermal method by varying the urea concentrations. Surface-sensitive X-ray photoelectron (XPS) and high-brilliance synchrotron-based X-ray absorption (XAS) spectroscopy is employed to probe the electronic and local structural modifications. Despite an incremental change of urea concentration, the chemical state of Ti4+ state is preserved within the experimental conditions. This is possible since the stabilized oxygen vacancies is accessible by hosting electrons at the neighbouring Ti atoms, and altering the Ti–N/O bond geometries. The XAS further revealed distinct orbital features within the Ti L3-edge in which t2g and eg peak splitting are highlighted the D2d symmetry of anatase. The incorporation of nitrogen enhanced N 2p–O 2p hybridization, weakening Ti 3d–O 2p hybridization. The fluctuating trend in the area ratio of eg (dz2) orbital infers direct evidence of the electron redistribution within Ti 3d–O 2p orbitals along the z-axis. These findings were corroborated in a similar trend shown at the pre-edge features, indicating the unprecedented charge carrier dynamics in this doped TiO2 system. These synchrotron-based measurements unveil the electronic modifications of N-TiO2, paving the way for the rational design of tunable heteroatom-doped metal oxides materials.
Original language | English |
---|---|
Article number | 105812 |
Journal | Surfaces and Interfaces |
Volume | 58 |
DOIs | |
Publication status | Published - 1 Feb 2025 |
Keywords
- N-doped TiO
- Orbital reconstruction, Electron redistribution
- Structural modification
- X-ray absorption spectroscopy