Synthesis of SrTiO3 and Al-doped SrTiO3via the deep eutectic solvent route
Date
2022-05-05
Authors
Adeyemi, Adedoyin N.
Venkatesh, Amrit
Xiao, Chengcan
Zhao, Zeqiong
Li, Ying
Cox, Tori
Jing, Dapeng
Osterloh, Frank E.
Zaikina, Julia V.
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Iowa State University Digital Repository, Ames IA (United States)
Abstract
SrTiO3 and aluminum-doped SrTiO3 are synthesized by calcination of metal salts dissolved in a deep eutectic solvent (DES) without any post-synthesis treatment. The DES used is the eutectic mixture of choline chloride (hydrogen bond acceptor) and malonic acid (hydrogen bond donor). Titanium(IV) oxide bis(2,4-pentanedionate) is utilized as the non-volatile, easy-to-handle, DES-soluble titanium precursor. The ammonia gas evolved during the calcination process provides a reducing atmosphere, resulting in the formation of Ti3+ and oxygen vacancies within the SrTiO3 matrix. According to UV-Vis spectroscopy and X-ray photoelectron spectroscopy, the amount of Ti3+ species and oxygen vacancies (VO) in the synthesized perovskite can be tuned by varying the duration of the calcination process and by adding Al3+ dopants. Solid state 27Al NMR spectroscopy and powder X-ray diffraction confirm the doping of aluminum into the octahedral site of the perovskite structure. Surface photovoltage spectroscopy confirms that Al3+ dopants can eliminate Ti3+ defects in Al-doped SrTiO3. Ultraviolet illumination experiments in water and aqueous methanol show that SrTiO3 and aluminum-doped SrTiO3, after modification with RhxCr2−xO3 or Pt co-catalysts, evolve small amounts of H2 (EQE of 0.0113–0.0173% at 375 nm) with only traces of O2 detected. The lack of photocatalytic activity is attributed to rapid electron-hole recombination in the oxygen vacancy-rich materials and to the lack of crystal facets that could aid charge separation.
Series Number
Journal Issue
Is Version Of
Versions
Series
IS-J 10796
Academic or Administrative Unit
Type
article
Comments
This article is published as Adeyemi, Adedoyin N., Amrit Venkatesh, Chengcan Xiao, Zeqiong Zhao, Ying Li, Tori Cox, Dapeng Jing, Aaron J. Rossini, Frank Osterloh, and Julia V. Zaikina. "Synthesis of SrTiO 3 and Al-doped SrTiO 3 via deep eutectic solvent route." Materials Advances (2022).
DOI: 10.1039/D2MA00404F.
Copyright 2022 The Author(s).
Attribution-NonCommercial 4.0 International (CC BY-NC 4.0).
Posted with permission.
DOE Contract Number(s): AC02-07CH11358; SC0015329.