Analysis of Indium Oxidation State on the Electronic Structure and Optical Properties of TiO2

Abstract

Due to the high formation energy of Indium interstitial defect in the TiO2 lattice, the most probable location for Indium dopant is substitutional sites. Replacing Ti by In atom in the anatase TiO2 shifted the absorption edge of TiO2 towards visible regime. Indium doping tuned the band structure of TiO2 via creating In 5p states. The In 5p states are successfully coupled with the O 2p states reducing the band gap. Increasing In doping level in TiO2 improved the visible light absorption. Compensating the charge imbalance by oxygen vacancy provided compensated Indium doped TiO2 model. The creation of oxygen vacancy widened the band gap, blue shifted the absorption edge of TiO2 and declined the UV light absorption. The 2.08% In in TiO2 is the optimal Indium doping concentration, providing suitable band structure for the photoelectrochemical applications and stable geometrical configuration among the simulated models. Our results provide a reasonable explanation for the improved photoactivity of Indium doped TiO2.

Indium-Doped TiO2 Photocatalysts with High-Temperature Anatase Stability

“…49 A recent GGA study presented an analysis of the band structure and DOS for stoichiometric and charge compensated In−TiO 2 anatase. 50 The details regarding the oxidation states, oxygen vacancy formation, reduction, and charge localization were not provided.…”

“…Charge compensation via oxygen vacancy formation in In-TiO2 rutile was previously studied using standard DFT, DFT+U and hybrid DFT 49 . A recent GGA study presented an analysis of the band structure and DOS for stoichiometric and charge compensated In-TiO2 anatase 50 . The details regarding the oxidation states, oxygen vacancy formation, reduction and charge localization were not provided.…”

A bioinspired optoelectronically engineered artificial neurorobotics device with sensorimotor functionalities

“…5). The proposed mechanism includes the modification of adsorption spectra of TiO 2 via substitution of an In-atom in TiO 2 structure (Ti 15 In 1 O 32 ) 28 . The following X-ray photoelectron spectroscopy (XPS) profile measurements (Fig.…”

Indium Oxides and Related Indium‐based Photocatalysts for Water Treatment: Materials Studied, Photocatalytic Performance, and Special Highlights

“…The doping location of indium ions has been said to most likely to be substitutional in the TiO 2 lattice, as the energy required to place indium in interstitial sites is high. [ 125 ] The addition of indium creates In 5p states in the TiO 2 band structure that couple with the O 2p states and therefore decrease the bandgap. Hence, a visible‐light photocatalyst can be obtained by the substitution of a Ti atom by In with increasing In content broadening the absorption.…”

“…Simultaneously, the creation of oxygen vacancies widens the bandgap and blue shifts the absorbance onset of TiO 2 . Therefore, an optimum In dopant level exists, whereby, for the calculations conducted by Khan et al, [ 125 ] an optimum of 2.08% In in TiO 2 was found.…”