Selective Catalytic Reduction of NO Using Phase-Pure Anatase, Rutile, and Brookite TiO Nanocrystals.

We demonstrate a facile selective synthesis of phase-pure anatase, rutile, and brookite nanocrystal polymorphs of titania (TiO) using a benign hydrothermal treatment of an industrial grade TiOSO precursor. Acetic acid (CHCOOH) is used for the synthesis of anatase, glycolic acid (HOCHCOOH) is used for rutile, and both glycolic acid and ammonium hydroxide (NHOH) are used for obtaining brookite. The detailed morphologies of the as-synthesized materials are determined from a combination of powder X-ray diffraction, transmission electron microscopy, and Raman spectroscopy.

Effect of Divalent Cations on the Interaction of Carboxylate Self-Assembled Monolayers.

Interactions between organic molecules in aqueous environments, whether in the fluid phase or adsorbed on solids, are often affected by the cations present in the solution. We investigated, at nanometer scale, how surface carboxylate interactions are influenced by dissolved divalent cations: Mg, Ca, Sr, and Ba. Self-assembled monolayer (SAM) surfaces with exposed terminations of alkyl, -CH, carboxylate, -COO , or dicarboxylate, -DiCOO, were deposited on gold-coated tips and substrates.

Nanoscale chemical mapping of oxygen functional groups on graphene oxide using atomic force microscopy-coupled infrared spectroscopy.

The unambiguous determination of the chemical functionality over graphene oxide (GO) is important to unleash its potential applications. However, the mapping of oxygen functionalities distribution remains to be unequivocally determined because of highly inhomogeneous non-stoichiometric structures and ultra-thin layers of GO. In this study, we report an experimental observation of the spatial distribution of oxygen functional groups on monolayer and multilayer GO using AFM-IR, atomic force microscopy coupled with infrared spectroscopy.

Specific Ion Effects on the Interaction of Hydrophobic and Hydrophilic Self-Assembled Monolayers.

Interactions between mineral surfaces and organic molecules are fundamental to life processes. The presence of cations in natural environments can change the behavior of organic compounds and thus alter the mineral-organic interfaces. We investigated the influence of Na, Mg, Ca, Sr, and Ba on the interaction between two models, self-assembled monolayers, that were tailored to have hydrophobic -CH or hydrophilic -COO(H) terminations.