We report the electrocatalysis of the chlorine evolution reaction (CER) on well-defined RuO2(110) and IrO2(110) surfaces. RuO2 and IrO2 are known for their capabilities to catalyze the CER. Until now, the CER measurements have only been reported on well-defined RuO2 surfaces and only at high Cl- concentrations. We present the CER measurement and the role of Cl- at lower concentration on single-orientation RuO2(110) and IrO2(110) films. We find that RuO2(110) is two orders of magnitude more active than IrO2(110).

We report the hydroxide (OH ad ) and oxide (O ad ) experimental electroadsorption free energies, their dependences on pH, and their correlations to the oxygen evolution reaction (OER) electrocatalysis on RuO 2 (110) surface. The Sabatier principle predicts that catalyst is most active when the intermediate stabilization is moderate, not too strong such that the bound intermediate disrupts the subsequent catalytic cycle, nor too weak such that the surface is ineffective.

The carrier effective mass plays a crucial role in modern electronic, optical, and catalytic devices and is fundamentally related to key properties of solids such as the mobility and density of states. Here we demonstrate a method to deterministically engineer the effective mass using spatial confinement in metallic quantum wells of the transition metal oxide IrO2.

We report the growth of superconducting Sr2RuO4 thin films by molecular-beam epitaxy on (110) NdGaO3 substrates with transition temperatures of up to 1.8 K. We calculate and experimentally validate a thermodynamic growth window for the adsorption-controlled growth of superconducting Sr2RuO4 epitaxial thin films. The growth window for achieving superconducting Sr2RuO4 thin films is narrow in growth temperature, oxidant pressure, and ruthenium-to-strontium flux ratio. © 2018 Author(s).

The perovskite ruthenate CaRuO3 has attracted considerable interest due to reports of possible non-Fermi-liquid behavior and its proximity to a magnetic quantum critical point, yet its ground state and electronic structure remain enigmatic. Here, we report measurements of the Fermi surface and quasiparticle dispersion in CaRuO3 through a combination of oxide molecular beam epitaxy and in situ angle-resolved photoemission spectroscopy.

Dimensionality and connectivity among octahedra play important roles in determining the properties, electronic structure, and phase transitions of transition-metal oxides. Here we demonstrate the epitaxial growth of (110)-oriented alternating layers of IrO2 and TiO2, both of which have the rutile structure. These (IrO2)n/(TiO2)2 superlattices consist of IrO6 and TiO6 octahedra tiled in a hyperconnected, edge- and corner-sharing network.

LaxBa1-xSnO3 is a promising transparent conducting oxide whose high mobility facilitates potential applications in transparent electronics, oxide electronics, and power electronics. Here, we report quantitative comparisons between angle-resolved photoemission and density functional theory, demonstrating a close agreement between calculations and the measured bulk electronic structure. Further measurements reveal upward band bending at the film-vacuum interface, while ultraviolet (UV) exposure is found to increase the surface electron density, similar to other oxides.

Epitaxial SrRuO3 and CaRuO3 films were grown under an excess flux of elemental ruthenium in an adsorption-controlled regime by molecular-beam epitaxy (MBE), where the excess volatile RuOx (x = 2 or 3) desorbs from the growth front leaving behind a single-phase film. By growing in this regime, we were able to achieve SrRuO3 and CaRuO3 films with residual resistivity ratios (Ï300 K/Ï4 K) of 76 and 75, respectively.

The superconducting properties of Sr1-xLaxCuO2 thin films are strongly affected by sample preparation procedures, including the annealing step, which are not always well controlled. We have studied the evolution of Cu L2,3 and O K edge x-ray absorption spectra (XAS) of Sr1-xLaxCuO2 thin films as a function of reducing annealing, both qualitatively and quantitatively.

Understanding how physicochemical properties of materials affect the oxygen evolution reaction (OER) has enormous scientific and technological implications for the OER electrocatalyst design. We present our investigation on the role of strain on the surface-oxygen interaction and the OER on well-defined single-termination SrIrO3 films. Our approach employs a combination of molecular-beam epitaxy, electrochemical characterizations, ambient-pressure X-ray photoelectron spectroscopy, and density functional theory (DFT).