CO oxidation of bare and TiO₂-coated NiO–Ni(OH)₂ nanoparticles

• Published in: Current applied physics Vol. 12; no. 2; pp. 429 - 433
• Main Authors: Nam, Jong Won, Kim, Kwang-Dae, Kim, Dong Wun, Seo, Hyun Ook, Kim, Young Dok, Lim, Dong Chan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2012; 한국물리학회
• Subjects: adsorption; nanoparticles; nickel; oxidation; physics; titanium dioxide; X-ray photoelectron spectroscopy; 물리학
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2011.07.044

CO oxidation reactivity of bare and TiO₂-coated nanoparticles consisting of both NiO and Ni(OH)₂ surfaces was studied. For the deposition of TiO₂, atomic layer deposition was used, and formation of three-dimensional domains of TiO₂ on NiO–Ni(OH)₂ could be identified. Based on the data of X-ray Photoelectron Spectroscopy, we suggest that upon TiO₂ deposition only Ni(OH)₂ was remained on the surface, whereas NiO surface disappeared. Both CO adsorption and CO oxidation took place on NiO–Ni(OH)₂ surfaces under our experimental conditions. CO adsorption was almost completely suppressed after TiO₂ deposition, whereas CO oxidation activity was maintained to large extent. It is proposed that bare NiO cannot be active for CO oxidation, and can only uptake CO under our experimental condition, whereas hydroxylated surface of NiO can be active for CO oxidation.