Copper doped TiO2 nanoparticles characterized by X-ray absorption spectroscopy, total scattering, and powder diffraction – a benchmark structure–property study

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Dalton Transactions

DOI:https://doi.org/10.1039/C3DT00122A· OSTI ID:1235464

Lock, Nina; Jensen, Ellen M. L.; Mi, Jianli; Mamakhel, Aref; Norén, Katarina; Qingbo, Meng; Iversen, Bo B.

Metal functionalized nanoparticles potentially have improved properties e.g. in catalytic applications, but their precise structures are often very challenging to determine. Here we report a structural benchmark study based on tetragonal anatase TiO₂ nanoparticles containing 0–2 wt% copper. The particles were synthesized by continuous flow synthesis under supercritical water–isopropanol conditions. Size determination using synchrotron PXRD, TEM, and X-ray total scattering reveals 5–7 nm monodisperse particles. The precise dopant structure and thermal stability of the highly crystalline powders were characterized by X-ray absorption spectroscopy and multi-temperature synchrotron PXRD (300–1000 K). The combined evidence reveals that copper is present as a dopant on the particle surfaces, most likely in an amorphous oxide or hydroxide shell. UV-VIS spectroscopy shows that copper presence at concentrations higher than 0.3 wt% lowers the band gap energy. The particles are unaffected by heating to 600 K, while growth and partial transformation to rutile TiO₂ occur at higher temperatures. Anisotropic unit cell behavior of anatase is observed as a consequence of the particle growth (a decreases and c increases).

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: FOREIGN
• OSTI ID: 1235464
• Journal Information: Dalton Transactions, Vol. 42, Issue 26; ISSN 1477-9226
• Publisher: Royal Society of Chemistry
• Country of Publication: United States
• Language: ENGLISH