Flat-surface-assisted and self-regulated oxidation resistance of Cu(111)

The formation of an ultraflat surface on copper thin films is important for suppressing the oxidation process, but the formation of multi-atomic steps and terraces is a result of the basic atomic stacking process and difficult to avoid. Here, we develop an innovative strategy for fabricating copper thin films with a semi-permanently oxidation-resistant surface. Comprehensive atomic-resolution microscopy reveals that our thin film consists mostly of flat surfaces and occasional mono-atomic steps. Our first principles calculations show that a mono-atomic step edge is as impervious as a flat surface to oxygen consistent with our experimental observations. Furthermore, the first principles calculations exhibit self-regulated oxidation resistance at the top surface layer: when the oxygen coverage of fcc sites of the surface exceeds 50%, the adsorbed oxygens on the top layer suppresses further adsorption of additional O atoms and renders the ultraflat Cu surface to be more oxidation resistant.

Structural-Intensified PtCoRh Spiral Nanowires as Highly Active and Durable Electrocatalysts for Methanol Oxidation

Platinum (Pt)-based nanocatalysts with high density of surface atomic steps hold great prospects in electrocatalysis, whereas the structural instability under harsh redox conditions is still a rigorous challenge. Here we...

Microscopic Identification of Surface Steps on SiC by Density-Functional Calculations

We have performed density-functional calculations in order to clarify atomic structures and energetics of surface steps on SiC. The obtained energetics of distinct step types on vicinal 3C-SiC(111) surfaces which correspond to 4H- and 6H-SiC(0001) surfaces reveals the atom-scale reason for the experimental observation in the past that the step morphology is straight for the SiC(0001) surfaces inclined toward the 〈1-100〉 direction while it is meandering for the 〈11-20〉 inclined surfaces. The calculations clarify the rebonding between upper- and lower-terrace edge atoms, which is decisive for the energetics of the atomic steps.

Tailored fabrication of triple-surface-features in well-crystalline BiOCl photocatalyst and their synergistic role in catalytic processes

The exposed active surface sites in photocatalysts, comprising low-coordinated atomic steps and atomic-level thickness, are vital to achieve efficient catalysis.

Laser Synthesis of Iridium Nanospheres for Overall Water Splitting

Engineering surface structure of catalysts is an efficient way towards high catalytic performance. Here, we report on the synthesis of regular iridium nanospheres (Ir NSs), with abundant atomic steps prepared by a laser ablation technique. Atomic steps, consisting of one-atom level covering the surface of such Ir NSs, were observed by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The prepared Ir NSs exhibited remarkably enhanced activity both for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acidic medium. As a bifunctional catalyst for overall water splitting, they achieved a cell voltage of 1.535 V @ 10 mA/cm2, which is much lower than that of Pt/C-Ir/C couple (1.630 V @ 10 mA/cm2).