Si(CC)₄‑Based Single-Crystalline Semiconductor: Diamond-like Superlight and Superflexible Wide-Bandgap Material for the UV Photoconductive Device

A wide-bandgap SiC₄ semiconductor with low density and high elasticity has been designed and characterized by ab initio molecular dynamics simulations and first-principles calculations. The through-space conjugation among the d orbitals of Si and the π* orbitals of ethynyl moieties can remarkably enhance the photoconductivity. This new-type superlight and superflexible semiconductor is predicted to have unique electronic, optical, and mechanical properties, and it is a quite promising material for the high-performance UV optoelectronic devices suitable for various practical demands in a complex environment

Identification of the Scaling Relations for Binary Noble-Metal Nanoparticles

There exist a great many varieties of nanoparticles whose catalytic activities can be widely adjusted by changing their composition, shape, and size. Nørskov’s concepts to correlate the d-band center, adsorption energy, and activation energy offer an innovative approach to efficiently investigate the catalytic properties. Taking binary noble-metal polyhedral nanoparticles as representative systems, we found from first-principles simulations that the well-established scaling relations of the adsorption energies for extended surfaces can be seamlessly extended to the nanoscale. A systematic investigation of the correlation relations of the adsorption energies between the AH_<i>X</i> groups and the corresponding A atoms in the binary noble-metal polyhedral nanoclusters of different compositions, shapes, and sizes clearly demonstrates the linear scaling relation. More remarkably, the scaling relation at the nanoscale can be effectively unified with the well-established scaling relations for extended surfaces. Such a description should be extremely helpful for the efficient screening of nanoparticles with superior catalytic properties

Dehydrogenation of Propane to Propylene by a Pd/Cu Single-Atom Catalyst: Insight from First-Principles Calculations

The catalytic properties of the single-Pd-doped Cu₅₅ nanoparticle toward propane dehydrogenation have been systemically investigated by first-principles calculations, and the possible reaction mechanisms and effects of the single and multiple Pd doping on the catalytic activity have been discussed. Calculations reveal that the low-energy catalytic conversion of propane to propylene by the Pd/Cu single-atom catalyst comprises the initial crucial C–H bond breaking at either the methyl or methylene group, the facile diffusion of detached H atoms on the Cu surface, and the subsequent C–H bond dissociation activation of the adsorbed propyl species. The single-Pd-doped Cu₅₅ nanoparticle shows remarkable activity toward C–H bond activation, and the presence of relatively inactive Cu surface is beneficial for the coupling and desorption of detached H atoms and can reduce side reactions such as deep dehydrogenation and C–C bond breaking. The single-Pd-doped Cu₅₅ cluster bears good balance between the maximum use of the noble metal and the activity, and it may serve as a promising single-atom catalyst toward selective dehydrogenation of propane

Feasible Catalytic Strategy for Writing Conductive Nanoribbons on a Single-Layer Graphene Fluoride

An accessible method for local reduction of graphene fluoride catalyzed by the Pt-coated nanotip with the assistance of a mixture of hydrogen and ethylene atmosphere is proposed and fully explored theoretically. Detailed mechanisms and roles of hydrogen and ethylene molecules in the cyclic reduction is discussed based on extensive first-principles calculations. It is demonstrated that the proposed cyclic reduction strategy is energetically favorable. This new strategy can be effectively applied in scanning probe lithography to fabricate electronic circuits at the nanoscale on graphene fluoride under mild conditions

Ammonia Electrosynthesis with High Selectivity under Ambient Conditions via a Li⁺ Incorporation Strategy

We report the discovery of a dramatically enhanced N₂ electroreduction reaction (NRR) selectivity under ambient conditions via the Li⁺ incorporation into poly­(<i>N</i>-ethyl-benzene-1,2,4,5-tetracarboxylic diimide) (PEBCD) as a catalyst. The detailed electrochemical evaluation and density functional theory calculations showed that Li⁺ association with the O atoms in the PEBCD matrix can retard the HER process and can facilitate the adsorption of N₂ to afford a high potential scope for the NRR process to proceed in the “[OLi⁺]·N₂H_<i>x</i>” alternating hydrogenation mode. This atomic-scale incorporation strategy provides new insight into the rational design of NRR catalysts with higher selectivity

Additional file 2: of Characterization of Mycobacterium tuberculosis isolates from Hebei, China: genotypes and drug susceptibility phenotypes

Detailed information about New and orphan spoligotype patterns isolated from 1017 MTB strains in Hebei. (XLSX 15 kb

Additional file 1: of Characterization of Mycobacterium tuberculosis isolates from Hebei, China: genotypes and drug susceptibility phenotypes

Primer information of the MIRU-VNTR loci in this study. (DOCX 15 kb