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Title: Selective Response of Mesoporous Silicon to Adsorbants with Nitro Groups

Abstract

We demonstrate that the electronic structure of mesoporous silicon is affected by adsorption of nitrobased explosive molecules in a compound-selective manner. This selective response is demonstrated by probing the adsorption of two nitro-based molecular explosives (trinitrotoluene and cyclotrimethylenetrinitramine) and a nonexplosive nitro-based aromatic molecule (nitrotoluene) on mesoporous silicon using soft X-ray spectroscopy. The Si atoms strongly interact with adsorbed molecules to form Si-O and Si-N bonds, as evident from the large shifts in emission energy present in the Si L2,3 X-ray emission spectroscopy (XES) measurements. Furthermore, we find that the energy gap (band gap) of mesoporous silicon changes depending on the adsorbant, as estimated from the Si L2,3 XES and 2p X-ray absorption spectroscopy (XAS) measurements. Our ab initio molecular dynamics calculations of model compounds suggest that these changes are due to spontaneous breaking of the nitro groups upon contacting surface Si atoms. This compound-selective change in electronic structure may provide a powerful tool for the detection and identification of trace quantities of airborne explosive molecules.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1053354
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Chemistry - A European Journal, 18(10):2912-2922
Additional Journal Information:
Journal Name: Chemistry - A European Journal, 18(10):2912-2922
Country of Publication:
United States
Language:
English
Subject:
Environmental Molecular Sciences Laboratory

Citation Formats

McLeod, John A, Kurmaev, Ernst Z, Sushko, Petr V, Boyko, Teak D, Levitsky, Igor A, and Moewes, Alexander. Selective Response of Mesoporous Silicon to Adsorbants with Nitro Groups. United States: N. p., 2012. Web. doi:10.1002/chem.201102084.
McLeod, John A, Kurmaev, Ernst Z, Sushko, Petr V, Boyko, Teak D, Levitsky, Igor A, & Moewes, Alexander. Selective Response of Mesoporous Silicon to Adsorbants with Nitro Groups. United States. doi:10.1002/chem.201102084.
McLeod, John A, Kurmaev, Ernst Z, Sushko, Petr V, Boyko, Teak D, Levitsky, Igor A, and Moewes, Alexander. Mon . "Selective Response of Mesoporous Silicon to Adsorbants with Nitro Groups". United States. doi:10.1002/chem.201102084.
@article{osti_1053354,
title = {Selective Response of Mesoporous Silicon to Adsorbants with Nitro Groups},
author = {McLeod, John A and Kurmaev, Ernst Z and Sushko, Petr V and Boyko, Teak D and Levitsky, Igor A and Moewes, Alexander},
abstractNote = {We demonstrate that the electronic structure of mesoporous silicon is affected by adsorption of nitrobased explosive molecules in a compound-selective manner. This selective response is demonstrated by probing the adsorption of two nitro-based molecular explosives (trinitrotoluene and cyclotrimethylenetrinitramine) and a nonexplosive nitro-based aromatic molecule (nitrotoluene) on mesoporous silicon using soft X-ray spectroscopy. The Si atoms strongly interact with adsorbed molecules to form Si-O and Si-N bonds, as evident from the large shifts in emission energy present in the Si L2,3 X-ray emission spectroscopy (XES) measurements. Furthermore, we find that the energy gap (band gap) of mesoporous silicon changes depending on the adsorbant, as estimated from the Si L2,3 XES and 2p X-ray absorption spectroscopy (XAS) measurements. Our ab initio molecular dynamics calculations of model compounds suggest that these changes are due to spontaneous breaking of the nitro groups upon contacting surface Si atoms. This compound-selective change in electronic structure may provide a powerful tool for the detection and identification of trace quantities of airborne explosive molecules.},
doi = {10.1002/chem.201102084},
journal = {Chemistry - A European Journal, 18(10):2912-2922},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {1}
}