@article {95,
	title = {Surface Photochemistry of Adsorbed Nitrate: The Role of Adsorbed Water in the Formation of Reduced Nitrogen Species on α-Fe2O3 Particle Surfaces.},
	journal = {Journal of Physical Chemistry A},
	volume = {118},
	year = {2014},
	note = {CAPLUS AN 2013:1898077(Journal; Online Computer File)},
	pages = {158 - 166},
	publisher = {American Chemical Society},
	abstract = {The surface photochem. of nitrate, formed from nitric acid adsorption, on hematite (α-Fe2O3) particle surfaces under different environmental conditions is investigated using XPS.  Following exposure of α-Fe2O3 particle surfaces to gas-phase nitric acid, a peak in the N1s region is seen at 407.4 eV; this binding energy is indicative of adsorbed nitrate.  Upon broadband irradn. with light (λ > 300 nm), the nitrate peak decreases in intensity as a result of a decrease in adsorbed nitrate on the surface.  Concomitant with this decrease in the nitrate coverage, there is the appearance of two lower binding energy peaks in the N1s region at 401.7 and 400.3 eV, due to reduced nitrogen species.  The formation as well as the stability of these reduced nitrogen species, identified as NO- and N-, are further investigated as a function of water vapor pressure.  Addnl., irradn. of adsorbed nitrate on α-Fe2O3 generates three nitrogen gas-phase products including NO2, NO, and N2O.  As shown here, different environmental conditions of water vapor pressure and the presence of mol. oxygen greatly influence the relative photoproduct distribution from nitrate surface photochem.  The atm. implications of these results are discussed. [on SciFinder(R)]},
	keywords = {surface photochem nitrate nitric acid adsorbate iron oxide particle},
	isbn = {1089-5639},
	author = {Nanayakkara, Charith E. and Jayaweera, Pradeep M. and Rubasinghege, Gayan and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {115,
	title = {Size-Dependent Changes in Sea Spray Aerosol Composition and Properties with Different Seawater Conditions.},
	journal = {Environmental Science \& Technology},
	volume = {47},
	year = {2013},
	note = {CAPLUS AN 2013:690844(Journal; Online Computer File)},
	pages = {5603 - 5612},
	publisher = {American Chemical Society},
	abstract = {Much uncertainty exists regarding the chem. diversity of particles in sea spray aerosol (SSA) and the degree of mixing between inorg. and org. species in individual SSA particles.  Single particle anal. of SSA particles was performed, integrating transmission electron microscopy with energy dispersive x-ray anal. and scanning transmission x-ray microscopy with near edge x-ray absorption fine structure spectroscopy, focusing on quantifying the relative fractions of different particle types from 30 nm to 1 μm.  SSA particles were produced from seawater in a unique ocean/atm. facility equipped with breaking waves.  Changes to SSA compn. and properties after adding biol. (bacteria, phytoplankton) and org. material (ZoBell growth media) were probed.  Sub-micrometer SSA particles could be sepd. into 2 distinct populations: one with a characteristic sea-salt core composed primarily of NaCl and an org. C and Mg2+ coating (SS-OC); and a second type consisting of org. C (OC) species more homogeneously mixed with cations and anions, but not Cl-.  SS-OC particles exhibited a range of sizes, compns., morphologies, and element distributions within each particle.  Following addn. of biol. and org. material to seawater, a change occurred in particle morphol. and crystn. behavior assocd. with increasing org. content for SS-OC particles.  The fraction of OC-type particles, mainly present at <180 nm, was dramatically enhanced with increased biol. activity.  These changes with size and seawater compn. have important implications for atm. processes, e.g., cloud droplet activation and heterogeneous reactivity. [on SciFinder(R)]},
	keywords = {size dependent change sea spray aerosol compn},
	isbn = {0013-936X},
	author = {Ault, Andrew P. and Moffet, Ryan C. and Baltrusaitis, Jonas and Collins, Douglas B. and Ruppel, Matthew J. and Cuadra-Rodriguez, Luis A. and Zhao, Defeng and Guasco, Timothy L. and Ebben, Carlena J. and Geiger, Franz M. and Bertram, Timothy H. and Prather, Kimberly A. and Grassian, Vicki H.}
}
@article {144,
	title = {Surface Chemistry of α-FeOOH Nanorods and Microrods with Gas-Phase Nitric Acid and Water Vapor: Insights into the Role of Particle Size, Surface Structure, and Surface Hydroxyl Groups in the Adsorption and Reactivity of α-FeOOH with Atmospheric Gases.},
	journal = {Journal of Physical Chemistry C},
	volume = {116},
	year = {2012},
	note = {CAPLUS AN 2012:668168(Journal; Online Computer File)},
	month = {2012///},
	pages = {12566 - 12577},
	publisher = {American Chemical Society},
	abstract = {Heterogeneous interactions of H2O and HNO3 on goethite, α-FeOOH, a component of mineral dust aerosol, are studied with simultaneous QCM measurements and ATR-FTIR spectroscopy.  Lab. synthesized α-FeOOH of varying sizes (microrods and nanorods) when exposed to gas phase H2O and HNO3 results in the uptake of these gases.  This combined approach of QCM measurements and ATR-FTIR spectroscopy allows for both quantification of the amt. of uptake and spectroscopic data that provides information on speciation of adsorbed products.  In the case of H2O, both microrods and nanorods take up H2O and that the total amts. of H2O, when normalized to surface area, are similar.  However, for HNO3 uptake, the satn. coverage of total and irreversibly bound HNO3 on microrods is higher than that on nanorods, a size effect which is attributed to surface structural changes that occur as a function of particle size.  Also, a study of the behavior of HNO3 reacted with α-FeOOH in aq. media was carried out such as to better understand the effects of atm. processing upon dispersal within the hydrosphere. [on SciFinder(R)]},
	keywords = {iron hydroxide oxide nanorod microrod nitric acid water adsorption},
	isbn = {1932-7447},
	author = {Wijenayaka, Lahiru A. and Rubasinghege, Gayan and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {159,
	title = {Sulfur Dioxide Adsorption on TiO2 Nanoparticles: Influence of Particle Size, Coadsorbates, Sample Pretreatment, and Light on Surface Speciation and Surface Coverage.},
	journal = {Journal of Physical Chemistry C},
	volume = {115},
	year = {2011},
	note = {CAPLUS AN 2010:1546849(Journal; Online Computer File)},
	month = {2011///},
	pages = {492 - 500},
	publisher = {American Chemical Society},
	abstract = {The adsorption of sulfur dioxide (SO2) on titanium dioxide (TiO2) nanoparticle surfaces at 296 K under a wide range of conditions has been investigated.  XPS is used to investigate the surface speciation and surface coverage of sulfur-contg. products on ca. 4 nm TiO2 anatase particles that remain on the surface following adsorption of SO2.  The effects of various environmental conditions of relative humidity, mol. oxygen, and broadband UV/vis irradn. as well as sample pretreatment were found to impact the speciation of adsorbed SO2 as well as the satn. coverage.  In particular, in the absence of light, the majority surface species upon SO2 adsorption is found to be adsorbed sulfite.  Broadband UV/vis irradn. during sulfur dioxide adsorption leads to an increase (nearly 2-fold) in the amt. of adsorbed sulfur species, as compared to expts. with no light, and results in the formation of adsorbed sulfate.  The formation of sulfate was quant. in the presence of mol. oxygen.  New surface species including chemisorbed mol. SO2 were obsd. on samples that have been reduced in vacuum through argon ion sputtering.  The total amt. of adsorbed sulfur was impacted by surface hydroxyl group coverage and molecularly adsorbed water layer.  Addnl., comparison of sulfur dioxide adsorption on 4 vs. 32 nm sized anatase nanoparticles showed that surface satn. coverages of adsorbed sulfite on the 4 nm particles was almost twice that of 32 nm particles as measured by the S2p:Ti2p peak area ratios, thus showing an increase in the inherent adsorption capacity of the smaller particles.  Proposed adsorption sites and mechanisms to account for the obsd. exptl. data are discussed. [on SciFinder(R)]},
	keywords = {adsorption sulfur dioxide titania nanoparticle surface speciation irradn},
	isbn = {1932-7447},
	author = {Baltrusaitis, Jonas and Jayaweera, Pradeep M. and Grassian, Vicki H.}
}
@article {160,
	title = {Sulfur Dioxide Adsorption on ZnO Nanoparticles and Nanorods.},
	journal = {Journal of Physical Chemistry C},
	volume = {115},
	year = {2011},
	note = {CAPLUS AN 2011:546775(Journal; Online Computer File)},
	month = {2011///},
	pages = {10164 - 10172},
	publisher = {American Chemical Society},
	abstract = {ZnO nanomaterials, nanoparticles, and nanorods, were synthesized over a wide range of sizes with relatively high yield (\~{}90-95\%).  The synthesis method allows for size control by varying the amt. of water used and morphol. control by varying the zinc precursor (zinc acetate for nanoparticles or zinc acetylacetonate for nanorods).  These nanomaterials were analyzed with powder x-ray diffraction and attenuated total reflection FTIR spectroscopy.  Sulfur dioxide adsorption on nanoparticles and nanorods of different size was then studied using volumetric measurements, transmission FTIR spectroscopy, and XPS.  Nanoparticles and nanorods of several different sizes were heated to 550{\textdegree} to remove surface-adsorbed org. ligands that remained after the synthesis prior to exposure to SO2.  Spectroscopic anal. revealed the formation of several surface species, including sulfate, sulfite, sulfide, and weakly bound SO2.  Quantifying surface speciation as well as the total amt. of adsorbed sulfur from XPS and volumetric data reveals that sulfur speciation as well as the total amt. of adsorbed sulfur is a function of particle size and morphol. [on SciFinder(R)]},
	keywords = {sulfur dioxide adsorption zinc oxide nanoparticle nanorod},
	isbn = {1932-7447},
	author = {Wu, Chia-Ming and Baltrusaitis, Jonas and Gillan, Edward G. and Grassian, Vicki H.}
}
@article {187,
	title = {Spatially Resolved Product Formation in the Reaction of Formic Acid with Calcium Carbonate (101̅4): The Role of Step Density and Adsorbed Water-Assisted Ion Mobility.},
	journal = {Langmuir},
	volume = {23},
	year = {2007},
	note = {CAPLUS AN 2007:521222(Journal)},
	month = {2007},
	pages = {7039 - 7045},
	publisher = {American Chemical Society},
	abstract = {The reaction of calcium carbonate (101̅4) single-crystal surfaces with formic acid (HCOOH) vapor was investigated using at. force microscopy (AFM) and XPS.  AFM images indicate the reaction produces rather well-defined crystallites, preferentially at step edges and at distinct angles to one another and mirroring the rhombohedral structure of the calcite surface, while exposing unreacted carbonate surface.  The size and surface d. of the crystallites depend upon substrate step d., exposure time, and relative humidity.  XPS data confirmed the crystallite compn. as the expected calcium formate product.  The AFM images show erosion and pit formation of the calcite surface in the vicinity of the product crystallites, clearly providing the spatially resolved characterization of the source of Ca ions.  AFM expts. exploring the effects of water vapor on the reacted surface show that the calcium formate crystallites are mobile under conditions of high relative humidity, combining to form larger crystallites and nanometer-sized crystals with an orthorhombohedral habit consistent with the α form, as confirmed by X-ray diffraction.  The implications for the reactions described here are discussed. [on SciFinder(R)]},
	keywords = {step density ion mobility reaction formic acid calcium carbonate},
	isbn = {0743-7463},
	author = {Usher, Courtney R. and Baltrusaitis, Jonas and Grassian, Vicki H.}
}
@article {181,
	title = {A Spectroscopic Study of Atmospherically Relevant Concentrated Aqueous Nitrate Solutions.},
	journal = {J. Phys. Chem. AJournal of Physical Chemistry A},
	volume = {111},
	year = {2007},
	note = {CAPLUS AN 2007:8813(Journal)},
	month = {2007///},
	pages = {544 - 548},
	publisher = {American Chemical Society},
	abstract = {Concd. aq. NO3- aerosols are present in the earth atm. due to heterogeneous reactions of sea salt and mineral dust aerosol with NOx (e.g., NO2, NO3, HNO3, N2O5).  Since the water content of these aerosols depends on relative humidity (RH), the compn. and NO3- concn. also depends on RH.  Unlike the original aerosols, aq. NO3- aerosols are photochem. active at solar wavelengths.  To better understand the NO3- chromophore in concd. aq. NO3- aerosols, the attenuated total reflection-Fourier transform IR spectroscopic (ATR-FTIR) and UV/VIS spectra of concd. NO3- solns. were measured over a large concn. range.  Both ATR-FTIR and UV/VIS spectroscopy showed changes in NO3- spectra with increasing concn.  Ab-initio calcns. were used to aid in assigning and interpreting these spectra.  From these data, it was predicted that aq. NO3- aerosols photoreactivity will strongly depend on RH since the mol. and electronic structure of NO3- becomes increasingly perturbed from that of the isolated ion in highly concd. atmospherically-relevant solns. [on SciFinder(R)]},
	keywords = {attenuated total reflectance Fourier transform IR spectroscopy analysis, particulate air pollution nitrate aerosol spectroscopic assessment, sea salt mineral dust atm reaction nitrate aerosol formation, spectroscopic assessment atm relevant concd aq nitrate soln, UV visible spectroscopy atm nitrate aerosol analysis},
	isbn = {1089-5639},
	author = {Hudson, Paula K. and Schwarz, Jaclyn and Baltrusaitis, Jonas and Gibson, Elizabeth R. and Grassian, Vicki H.}
}
@article {188,
	title = {Surface Reactions of Carbon Dioxide at the Adsorbed Water-Oxide Interface.},
	journal = {J. Phys. Chem. CJournal of Physical Chemistry C},
	volume = {111},
	year = {2007},
	note = {CAPLUS AN 2007:1033025(Journal)},
	month = {2007///},
	pages = {14870 - 14880},
	publisher = {American Chemical Society},
	abstract = {In this study, FTIR spectroscopy is used to investigate surface reactions of carbon dioxide at the adsorbed water-oxide interface.  In particular, FTIR spectra following CO2 adsorption in the presence and absence of coadsorbed water on hydroxylated nanoparticulate Fe2O3 and γ-Al2O3 at 296 K are reported.  In the absence of coadsorbed water, CO2 reacts with surface O-H groups to form adsorbed bicarbonate on the surface.  In the presence of coadsorbed water, this reaction is blocked as water hydrogen bonds to the reactive M-OH sites.  Instead, CO2 reacts with adsorbed water to yield adsorbed carbonate and protonated surface hydroxyl groups, M-OH2+, through a proposed carbonic acid intermediate.  The carbonate spectra recorded between 10 and 90\% RH are nearly identical to that of carbonate adsorbed on these surfaces in the presence of the liq. water.  FTIR isotope studies show that there is extensive exchange between oxygen in adsorbed water and oxygen atoms in both adsorbed carbonate and gas-phase carbon dioxide.  On the basis of these exptl. results along with quantum chem. calcns., a mechanism is proposed for surface reactions of carbon dioxide at the adsorbed water-oxide interface. [on SciFinder(R)]},
	keywords = {surface reaction carbon dioxide adsorbed water oxide interface},
	isbn = {1932-7447},
	author = {Baltrusaitis, Jonas and Schuttlefield, Jennifer D. and Zeitler, Elizabeth and Jensen, Jan H. and Grassian, Vicki H.}
}
@article {192,
	title = {Surface reactions of carbon dioxide at the adsorbed water-iron oxide interface.},
	journal = {Journal of Physical Chemistry B},
	volume = {109},
	year = {2005},
	note = {CAPLUS AN 2005:466038(Journal)},
	month = {2005///},
	pages = {12227 - 12230},
	publisher = {American Chemical Society},
	abstract = {Despite the fact that CO2 is an abundant atm. gas with profound environmental implications, there is little information on the reaction of CO2 at the adsorbed water-oxide interface.  In this study, the chem. of CO2 at the adsorbed water-iron oxide interface was investigated with FTIR spectroscopy.  As shown here, the thin water layer on the iron oxide surface plays an important role in the surface chem. of CO2.  In particular, adsorbed water enhances CO2 uptake, undergoes isotope exchange with CO2 in O(18)-labeled expts., and influences the chem. nature of the predominant adsorbed product on the surface from bicarbonate to carbonate.  The resultant thin water film is acidic in nature from the reaction of CO2.  The IR spectrum recorded of adsorbed carbonate at the adsorbed water-iron oxide interface is remarkably similar to that at the bulk liq. water-iron oxide interface.  Since reactions in thin water films estd. to be ≈2 layers will play a role in a no. of environmental processes, it is essential to understand the chem. of these "wet" interfaces with atm. gases. [on SciFinder(R)]},
	keywords = {carbon dioxide surface reaction water adsorbate iron oxide},
	isbn = {1520-6106},
	author = {Baltrusaitis, Jonas and Grassian, Vicki H.}
}
