@article {54,
	title = {Hematite decorated multi-walled carbon nanotubes (α-Fe2O3/MWCNTs) as sorbents for Cu(II) and Cr(VI): comparison of hybrid sorbent performance to its nanomaterial building blocks.},
	journal = {RSC Advances},
	volume = {6},
	year = {2016},
	note = {CAPLUS AN 2016:1655141(Journal; Online Computer File)},
	month = {2016},
	pages = {99997 - 100007},
	publisher = {Royal Society of Chemistry},
	abstract = {Major hurdles in the application of engineered nanomaterials for water treatment include loss of reactive surface area arising from particle aggregation and the development of application platforms that limit their potential release into the treated water supply.  Here, we develop hybrid nanostructures through the growth of hematite (α-Fe2O3) nanoparticles, which are recognized sorbents for various heavy metals, on multi-walled carbon nanotubes (MWCNTs).  The hybrid nanostructures were synthesized via hydrolysis of ferric nitrate in the presence of carboxylated MWCNTs, and their activity as sorbents toward Cu(II) and chromate (CrO42-) was examd. as a function of pH (i.e., pH-edge expts.) and initial metal concn. (i.e., adsorption isotherms).  Characterization of α-Fe2O3/MWCNT nanostructures via Raman spectroscopy and transmission electron microscopy (TEM) with selected area electron diffraction (SAED) confirmed the deposited iron phase as α-Fe2O3.  Further, complementary acid digestions and TEM imaging revealed that the amt. (0.1 and 0.5 g g-1 α-Fe2O3/MWCNT) and size [5.9 ({\textpm}1.1) and 8.9 ({\textpm}1.5) nm, resp.] of α-Fe2O3 nanoparticles immobilized on MWCNTs were tunable during synthesis.  Generally, mass-normalized concns. of adsorbed Cu(II) and CrO42- were greatest for α-Fe2O3/MWCNT hybrids relative to adsorption on either carboxylated MWCNTs or freely suspended α-Fe2O3 nanoparticles, with evidence implicating α-Fe2O3 as the active sorbent phase in hybrid materials.  Indeed, per unit mass of available α-Fe2O3, hybrid sorbents exhibited capacities comparable to or exceeding most other iron-based sorbents for Cu(II) and CrO42- (from 220 to 470 mg Cu(II) per g α-Fe2O3 and 60 mg CrO42- per g α-Fe2O3, resp., at pH 6 and 20 {\textdegree}C).  The enhanced sorption capacity of the hybrid nanostructures is due, at least in part, to the greater available surface area of α-Fe2O3 nanoparticles immobilized on MWCNTs when compared to their more extensively aggregated state in suspension.  Notable differences in the pH-dependent trends of Cu(II) and CrO42- uptake on α-Fe2O3/MWCNT hybrids, along with differences in zeta potential measurements across pH, also suggest that the immobilized α-Fe2O3 nanoparticles may exhibit unique surface reactivity relative to their freely suspended analogs as a result of their assocn. with the neg. charged MWCNT surface. [on SciFinder(R)]},
	keywords = {hematite MWCNT copper chromium hybrid sorbent nanomaterial building block},
	isbn = {2046-2069},
	author = {Verdugo, Edgard M. and Xie, Yang and Baltrusaitis, Jonas and Cwiertny, David M.}
}
@article {106,
	title = {Horizontal Attenuated Total Reflectance Fourier Transform Infrared and X-ray Photoelectron Spectroscopy Measurements of Water Adsorption on Oxidized Tin(II) Sulfide (SnS) Surfaces.},
	journal = {Journal of Physical Chemistry C},
	volume = {117},
	year = {2013},
	note = {CAPLUS AN 2012:1849049(Journal; Online Computer File)},
	pages = {472 - 482},
	publisher = {American Chemical Society},
	abstract = {Tin(II) sulfide (SnS) is considered to be a promising optoelectronic material due to its narrow band gap, strong optical absorption, low cost and nontoxic and chem. inert characteristics.  As an inherently stable compd., SnS surfaces are expected to be hydrophobic by nature.  However, exposure of pristine SnS surfaces to air inevitably leads to surface oxidn. which can affect the mineral{\textquoteright}s dissoln., reactivity, optical and electronic properties as well as hydrophobicity.  In the present study, water adsorption measurements on oxidized SnS thin films were performed using horizontal attenuated total reflection Fourier transform IR (HATR-FTIR) spectroscopy.  XPS anal. allowed for characterization of the SnS surface compn. before water vapor exposure and identification of any changes that occurred to the surface after water vapor exposure.  XPS results are consistent with water adsorption occurring on SnS surfaces contg. hydroxyl and carbonate groups.  Addnl., XPS anal. showed that exposure of SnS to water vapor resulted in no significant changes to the original surface compn.  Quant. water adsorption measurements using HATR-FTIR spectroscopy show that the oxidized SnS surface exhibits a slightly hydrophilic nature, demonstrating multilayer water adsorption at high relative humidity (RH) values.  Exptl. water adsorption data were fit using the Brunauer-Emmett-Teller (BET) and Freundlich adsorption models.  From these model fits, details of monolayer water adsorption and the water adsorption mechanisms were extd. to provide a better understanding of gas/surface adsorption on oxidized SnS surfaces.  Results suggest that water adsorption on SnS powder occurs in three distinct regimes, including sub-monolayer water adsorption up to monolayer coverage at 13\% RH, followed by filling of mesopores (13-76\% RH) and finally multilayer water adsorption ( > 76\% RH) via filling of macropores.  This study represents the first report of in situ water adsorption measurements on SnS as a function of relative humidity, illustrating how oxidized surface species can alter the hydrophobic nature of SnS surfaces. [on SciFinder(R)]},
	keywords = {horizontal attenuated total reflectance FTIR XPS, water adsorption oxidized tin sulfide surface},
	isbn = {1932-7447},
	author = {Hatch, Courtney D. and Christie, Matthew J. and Weingold, Robert M. and Wu, Chia-Ming and Cwiertny, David M. and Baltrusaitis, Jonas.}
}
