Properties of aqueous nitrate and nitrite from x-ray absorption spectroscopy

Journal Article · Fri Aug 28 04:00:00 EDT 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4928867· OSTI ID:22493583

Smith, Jacob W.; Lam, Royce K.; Shih, Orion ^[1]; Rizzuto, Anthony M. ^[2]; Prendergast, David ^[3]

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1. National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)
2. Department of Chemistry, University of California, Berkeley, California 94720 (United States)
3. The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

Nitrate and nitrite ions are of considerable interest, both for their widespread use in commercial and research contexts and because of their central role in the global nitrogen cycle. The chemistry of atmospheric aerosols, wherein nitrate is abundant, has been found to depend on the interfacial behavior of ionic species. The interfacial behavior of ions is determined largely by their hydration properties; consequently, the study of the hydration and interfacial behavior of nitrate and nitrite comprises a significant field of study. In this work, we describe the study of aqueous solutions of sodium nitrate and nitrite via X-ray absorption spectroscopy (XAS), interpreted in light of first-principles density functional theory electronic structure calculations. Experimental and calculated spectra of the nitrogen K-edge XA spectra of bulk solutions exhibit a large 3.7 eV shift between the XA spectra of nitrate and nitrite resulting from greater stabilization of the nitrogen 1s energy level in nitrate. A similar shift is not observed in the oxygen K-edge XA spectra of NO{sub 3}{sup −} and NO{sub 2}{sup −}. The hydration properties of nitrate and nitrite are found to be similar, with both anions exhibiting a similar propensity towards ion pairing.

• OSTI ID: 22493583
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 8 Vol. 143; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
AEROSOLS
ANIONS
AQUEOUS SOLUTIONS
CHEMISTRY
DENSITY FUNCTIONAL METHOD
ELECTRONIC STRUCTURE
ENERGY LEVELS
EV RANGE
HYDRATION
NITRITES
NITROGEN
NITROGEN CYCLE
OXYGEN
SODIUM NITRATES
STABILIZATION
VISIBLE RADIATION
X-RAY SPECTROSCOPY