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Strong SERS Performances of Ultrathin α‐Co(OH) 2 Nanosheets to the Toxic Organophosphorus Molecules and Hydrogen Bond‐Induced Charge Transfer Mechanism
Author(s) -
Zhao Qian,
Liu Guangqiang,
Zhang Hongwen,
Li Yue,
Cai Weiping
Publication year - 2018
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201700709
Subject(s) - materials science , molecule , raman scattering , adsorption , substrate (aquarium) , photochemistry , hydrogen bond , raman spectroscopy , nanosheet , inorganic chemistry , nanotechnology , chemistry , organic chemistry , physics , oceanography , optics , geology
The ultrathin α‐Co(OH) 2 nanosheets are fabricated via homogeneous precipitation from the cobalt nitrate solution. The nanosheet‐built film is used as the substrate for Raman detection of toxic organophosphorus molecules. Such nanosheets are of strong surface enhancement Raman scattering (SERS) effect to the molecules that can be captured by the hydroxyls on the nanosheets. The enhancement factor is up to 2.0 × 10 3 . Typically, for the triphenylphosphine oxide (TPPPO) and 3,3‐diethylthiatricarbocyanine iodide (DTTCI) which both can be used as hydrogen bond acceptors and form hydrogen bonds with α‐Co(OH) 2 on the nanosheets' surface, the detection are to 0.35 ppm. The Raman peak intensity shows a linear relation with logarithmic DTTCI concentration, due to Temkin adsorption of DTTCI molecules on the nanosheets, and exhibits a linear double logarithmic relation with TPPPO concentration, due to Freundlich‐type adsorption. Further analysis reveal that such enhancement effect is attributed to the hydrogen bond‐induced formation of new excited state in the test molecules, which induces the charge transfer and hence magnifies the test molecules' polarizability. This work not only provides an effective substrate for SERS‐based detection of toxic organophosphorus molecules but also presents a new approach to design of the highly efficient nonmetal SERS‐active materials.