Atomically dispersed Iridium on MoC as an efficient and stable alkaline hydrogen oxidation reaction catalyst.

Hydroxide exchange membrane fuel cells (HEMFCs) have the advantages of using cost-effective materials, but hindered by the sluggish anodic hydrogen oxidation reaction (HOR) kinetics. Here, we report an atomically dispersed Ir on MoC nanoparticles supported on carbon (Ir-MoC/C) as highly active and stable HOR catalysts. The specific exchange current density of Ir-MoC/C is 4.

Dual-Atom Metal and Nonmetal Site Catalyst on a Single Nickel Atom Supported on a Hybridized BCN Nanosheet for Electrochemical CO Reduction to Methane: Combining High Activity and Selectivity.

Atomically dispersed nitrogen-coordinated transition-metal sites supported on graphene (TM-N-C) offer promising potential for the electrochemical carbon dioxide reduction reaction (CORR). However, a few TM-N-C single-atom catalysts (SAC) are capable of reducing CO to multielectron products with high activity and selectivity. Herein, using density functional theory calculations, we investigated the electrocatalytic performance of a single TM atom embedded into a defective BCN nanosheet for CORR.

Iridium metallene oxide for acidic oxygen evolution catalysis.

Exploring new materials is essential in the field of material science. Especially, searching for optimal materials with utmost atomic utilization, ideal activities and desirable stability for catalytic applications requires smart design of materials' structures. Herein, we report iridium metallene oxide: 1 T phase-iridium dioxide (IrO) by a synthetic strategy combining mechanochemistry and thermal treatment in a strong alkaline medium.

Carbon dots dominated photoelectric surface in titanium dioxide nanotube/nitrogen-doped carbon dot/gold nanocomposites for improved photoelectrochemical water splitting.

The dynamic behavior of electron-hole pairs at the interface of the nanocomposites is important for photoelectrochemical catalysis, but it is difficult to characterize. Here we construct a ternary titanium dioxide/nitrogen-doped carbon dot/gold (TiO/NCD/Au) complex as the model catalyst to investigate the kinetic indexes at their interfaces. Under irradiation (200 mW cm), the photocurrent density of TiO/NCD/Au is 10.

Regulating Electronic Spin Moments of Single-Atom Catalyst Sites via Single-Atom Promoter Tuning on S-Vacancy MoS for Efficient Nitrogen Fixation.

The electrocatalytic activity of transition-metal (TM)-based catalysts is correlated with the spin states of metal atoms. However, developing a way to manipulate spin remains a great challenge. Using first-principles calculations, we first report the crucial role of the spin of exposed Mo atoms around an S-vacancy in the electrocatalytic dinitrogen reduction reaction on defective MoS nanosheets and propose a novel strategy for regulating the electronic spin moments by tuning a single-atom promoter (SAP).

Synergistic Effect of Boron Nitride and Carbon Domains in Boron Carbide Nitride Nanotube Supported Single-Atom Catalysts for Efficient Nitrogen Fixation.

Developing the low-cost and efficient single-atom catalysts (SACs) for nitrogen reduction reaction (NRR) is of great importance while remains as a great challenge. The catalytic activity, selectivity and durability are all fundamentally related to the elaborate coordination environment of SACs. Using first-principles calculations, we investigated the SACs with single transition metal (TM) atom supported on defective boron carbide nitride nanotubes (BCNTs) as NRR electrocatalysts.

Synergistic Effect of Surface-Terminated Oxygen Vacancy and Single-Atom Catalysts on Defective MXenes for Efficient Nitrogen Fixation.

The production of ammonia (NH) from molecular dinitrogen (N) under ambient conditions is of great significance but remains as a great challenge. Using first-principles calculations, we have investigated the potential of using a transition metal (TM) atom embedded on defective MXene nanosheets (TiCO and TiCO with a Ti vacancy) as a single-atom electrocatalyst (SAC) for the nitrogen reduction reaction (NRR). The TiCO nanosheet with Mo and W embedded, and the TiCO nanosheet with Cr, Mo, and W embedded, can significantly promote the NRR while suppressing the competitive hydrogen evolution reaction, with the low limiting potential of -0.

One-Step Direct Fixation of Atmospheric CO by Si-H Surface in Solution.

The efficient conversion of carbon dioxide (CO) into useful chemicals has important practical significance for environmental protection. Until now, direct fixation of atmospheric CO needs first extraction from the atmosphere, an energy-intensive process. Silicon (or Si-H surface), Earth-abundant, low-cost and non-toxic, is a promising material for heterogeneous CO chemical fixation.

Rhodium Nanoparticles/F-Doped Graphene Composites as Multifunctional Electrocatalyst Superior to Pt/C for Hydrogen Evolution and Formic Acid Oxidation Reaction.

Highly efficient electrocatalysis for clean, efficient, and sustainable energy supply, such as hydrogen evolution reaction (HER) and formic acid oxidation reaction (FAOR), has drawn enthusiastic and worldwide attention. Universal and efficient electrocatalysts for these reactions are essential elements for the development of renewable and clean energy technologies. Herein, we show the design and fabrication of the rhodium nanoparticles modified fluorine-doped graphene (Rh/F-graphene) catalyst using silicon nanowires (SiNWs) as the sacrifice template.

Simple and sensitive electrogenerated chemiluminescence peptide-based biosensor for detection of matrix metalloproteinase 2 released from living cells.

A simple and sensitive electrogenerated chemiluminescence biosensor was developed to monitor matrix metalloproteinase 2 (MMP-2) by employing a specific peptide (CGPLGVRGK) as a molecular recognition substrate. Bis(2,2'-bipyridine)-4'-methyl-4-carboxybipyridine-ruthenium N-succinimidyl ester-bis(hexafluorophosphate) (Ru(bpy)2(mcbpy-O-Su-ester)(PF6)2 (Ru1) was used as ECL-emitting species and covalently labeled onto the peptide through NH2-containing lysine on the peptide via acylation reaction to form Ru1-peptide as an ECL probe. An ECL peptide-based biosensor was fabricated by self-assembling the ECL probe onto the surface of gold electrode.

Sensitive and versatile electrogenerated chemiluminescence biosensing platform for protein kinase based on Ru(bpy)3(2+) functionalized gold nanoparticles mediated signal transduction.

A novel, sensitive and versatile electrogenerated chemiluminescence biosensing platform is developed for monitoring activity and inhibition of protein kinase based on Ru(bpy)3(2+) functionalized gold nanoparticles (Ru(bpy)3(2+)-AuNPs) mediated signal transduction. Ru(bpy)3(2+)-AuNPs were formed by functionalizing AuNPs with Ru(bpy)3(2+) through electrostatic interactions and were used as thiol-versatile signal probe. Casein kinase II (CK2) and cAMP-dependent protein kinase (PKA), two classical protein kinase implicated in disease, were chosen as model protein kinases while a CK2-specific peptide (CRRRADDSDDDDD) and a PKA-specific peptide (CLRRASLG) were employed as molecular substrate for CK2 and PKA, respectively.

A network analysis of food flows within the United States of America.

The world food system is globalized and interconnected, in which trade plays an increasingly important role in facilitating food availability. We present a novel application of network analysis to domestic food flows within the USA, a country with global importance as a major agricultural producer and trade power. We find normal node degree distributions and Weibull node strength and betweenness centrality distributions.