First-principles study of electronic structures and optical properties of Cu, Ag, and Au-doped anatase TiO2

TL;DR

This study uses first-principles calculations to analyze how doping anatase TiO2 with Cu, Ag, and Au alters its electronic structure and enhances its visible light absorption, potentially improving its photocatalytic applications.

Contribution

It provides detailed insights into the electronic and optical modifications caused by Cu, Ag, and Au doping in anatase TiO2, revealing new states and shifted absorption edges.

Findings

Cu doping enhances d states near valence band top

Ag and Au doping introduce new states in the band gap

Doped TiO2 shows shifted absorption to 400-1000 nm

Abstract

We perform first-principles calculations to investigate the band structure, density of states, optical absorption, and the imaginary part of dielectric function of Cu, Ag, and Au-doped anatase TiO2 in 72 atoms systems. The electronic structure results show that the Cu incorporation can lead to the enhancement of d states near the uppermost of valence band, while the Ag and Au doping cause some new electronic states in band gap of TiO2. Meanwhile, it is found that the visible optical absorptions of Cu, Ag, and Au-doped TiO2, are observed by analyzing the results of optical properties,.which locate in the region of 400-1000 nm. The absorption band edges of Cu, Ag, and Au-doped TiO2 shift to the long wavelength region compared with the pure TiO2. Furthermore, according to the calculated results, we propose the optical transition mechanisms of Cu, Ag, and Au-doped TiO2, respectively. Our results show that the visible light response of TiO2 can be modulated by substitutional doping of Cu, Ag, and Au.