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Surfactant‐Assisted Hollowing of Cu Nanoparticles Involving Halide‐Induced Corrosion–Oxidation Processes
Author(s) -
Huang ChihChia,
Hwu Jih Ru,
Su WuChou,
Shieh DarBin,
Tzeng Yonhua,
Yeh ChenSheng
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200501484
Subject(s) - nanoshell , nanoparticle , halide , wetting , oxide , chemical engineering , pulmonary surfactant , materials science , absorption spectroscopy , absorption (acoustics) , contact angle , copper , chemistry , inorganic chemistry , nanotechnology , composite material , metallurgy , optics , physics , engineering
We have demonstrated a simple fabrication of hollow nanoparticles by halide‐induced corrosion oxidation with the aid of surfactants. Cuprous oxide Cu 2 O nanoshells can be generated by simply mixing Cu nanoparticles with alkyltrimethylammonium halides at 55 °C for 16 min. The hollowing mechanism proposed is that absorption of surfactants onto the Cu surface facilitates the formation of the void interior through an oxidative etching process. Upon extending the reaction up to 4 h, fragmentation, oxidation, and self‐assembly were observed and the CuO ellipsoidal structures were formed. The headgroup lengths of the surfactants influenced the degree of CuO ellipsoidal formation, whereby longer surfactants favored the generation of ellipsoids. Optical absorption measured by UV‐visible spectroscopy was used to monitor both oxidation courses of Cu→Cu 2 O and Cu 2 O→CuO and to determine the band‐gap energies as 2.4 eV for Cu 2 O nanoshells and 1.89 eV for CuO ellipsoids. For the contact‐angle measurements, the wettability changed from hydrophilicity (18°) to hydrophobicity (140°) as the Cu 2 O nanoshells shifted to CuO ellipsoids.