Mercury-Mediated Epitaxial Accumulation of Au Atoms for Stained Hydrogel-Improved Mercury Monitoring.

Trivalent Au ions are easily reduced to be zerovalent atoms by coexisting reductant reagents, resulting in the subsequent accumulation of Au atoms and formation of plasmonic nanostructures. In the absence of stabilizers or presence of weak stabilizers, aggregative growth of Au nanoparticles (NPs) always occurs, and unregular multidimensional Au materials are consequently constructed. Herein, the addition of nanomole-level mercury ions can efficiently prevent the epitaxial accumulation of Au atoms, and separated Au NPs with mediated morphologies and superior plasmonic characteristics are obtained.

Kinetic Understanding of Catalytic Selectivity and Product Distribution of Electrochemical Carbon Dioxide Reduction Reaction.

CO can be electrochemically reduced to different products depending on the nature of catalysts. In this work, we report comprehensive kinetic studies on catalytic selectivity and product distribution of the CO reduction reaction on various metal surfaces. The influences on reaction kinetics can be clearly analyzed from the variation of reaction driving force (binding energy difference) and reaction resistance (reorganization energy).

Chiral nanocrystals grown from MoS nanosheets enable photothermally modulated enantioselective release of antimicrobial drugs.

The transfer of the concept of chirality from molecules to synthesized nanomaterials has attracted attention amongst multidisciplinary teams. Here we demonstrate heterogeneous nucleation and anisotropic accumulation of Au nanoparticles on multilayer MoS planes to form chiroptically functional nanomaterials. Thiol amino acids with chiral conformations modulate asymmetric growth of gold nanoarchitectures on seeds of highly faceted Au/MoS heterostructures.

Co-Doped Mn O Nanocubes via Galvanic Replacement Reactions for Photocatalytic Reduction of CO with High Turnover Number.

The synthesis of Co-doped Mn O nanocubes was achieved via galvanic replacement reactions for photo-reduction of CO . Co@Mn O nanocubes could efficiently photo-reduce CO to CO with a remarkable turnover number of 581.8 using [Ru(bpy) ]Cl  ⋅ 6H O as photosensitizer and triethanolamine as sacrificial agent in acetonitrile and water.

Technologies and perspectives for achieving carbon neutrality.

Global development has been heavily reliant on the overexploitation of natural resources since the Industrial Revolution. With the extensive use of fossil fuels, deforestation, and other forms of land-use change, anthropogenic activities have contributed to the ever-increasing concentrations of greenhouse gases (GHGs) in the atmosphere, causing global climate change. In response to the worsening global climate change, achieving carbon neutrality by 2050 is the most pressing task on the planet.

Theoretical Insights on Au-based Bimetallic Alloy Electrocatalysts for Nitrogen Reduction Reaction with High Selectivity and Activity.

Electrochemical reduction of nitrogen to produce ammonia at moderate conditions in aqueous solutions holds great prospect but also faces huge challenges. Considering the high selectivity of Au-based materials to inhibit competitive hydrogen evolution reaction (HER) and high activity of transition metals such as Fe and Mo toward the nitrogen reduction reaction (NRR), it was proposed that Au-based alloy materials could act as efficient catalysts for N fixation based on density functional theory simulations. Only on Mo Au(111) surface the adsorption of N is stronger than H atom.

Revealing practical specific capacity and carbonyl utilization of multi-carbonyl compounds for organic cathode materials.

Organic carbonyl compounds are regarded as promising candidates for next-generation rechargeable batteries due to their low cost, environmentally benign nature, and high capacity. The carbonyl utilization is a key issue that limits the practical specific capacity of multi-carbonyl compounds. In this work, a combination of thermodynamic computation and electronic structure analysis is carried out to study the influence of carbonyl type and carbonyl number on the electrochemical performance of a series of multi-carbonyl compounds by using density functional theory (DFT) calculations.

A thermodynamic and kinetic study of the catalytic performance of Fe, Mo, Rh and Ru for the electrochemical nitrogen reduction reaction.

The electrochemical reduction of N2 is a promising reaction candidate for the ammonia synthesis process. Density functional theory simulations are carried out to study the reaction thermodynamics and kinetics for a better understanding of the catalytic performance of Fe, Mo, Rh, and Ru electrodes. The distal pathway is the most likely reaction pathway for nitrogen reduction on transition metal surfaces according to the computed reaction free energies.

Theoretical understanding of the electrochemical reaction barrier: a kinetic study of CO reduction reaction on copper electrodes.

The electrochemical reduction of CO is a promising route for converting intermittent renewable energy into storable fuels and useful chemical products. A theoretical investigation of the reaction mechanism and kinetics is beneficial for understanding the electrocatalytic activity and selectivity. In this report, a kinetic model based on Marcus theory is developed to compute the potential-dependent reaction barrier of the elementary concerted proton-electron transfer steps of electrochemical CO reduction reactions, different from the previous hydrogen atom transfer model.

A Density Functional Theoretical Study on the Charge-Transfer Enhancement in Surface-Enhanced Raman Scattering.

The chemical enhancement due to ground-state charge transfer (GSCT) and photon-driven charge transfer (PDCT) in surface-enhanced Raman scattering (SERS) has been investigated by density functional theory. Para-substituted thiophenol derivatives adsorbed on silver and gold surfaces are selected as model systems to evaluate the chemical enhancement factor. By changing the functional groups on thiophenol, we are allowed to modulate the chemical interactions between the thiophenol and the metal cluster in both ground state and charge transfer excited state.

Access to Multisubstituted Furan-3-carbothioates via Cascade Annulation of α-Oxo Ketene Dithioacetals with Isoindoline-1,3-dione-Derived Propargyl Alcohols.

A Brønsted acid-promoted, unprecedented formal (3 + 2) annulation strategy for the synthesis of multisubstituted furan-3-carbothioates is reported. This transformation represents the first regioselective annulation of α-oxo ketene dithio-acetals as 1,3-bis-nucleophiles in a cascade manner. The choice of isoindoline-1,3-dione-derived propargyl alcohols is crucial to the uncommon annulation mode between an alkyne-type bis-electrophile and a 1,3-bis-nucleophile under metal-free conditions.

Molecular Design of Phenanthrenequinone Derivatives as Organic Cathode Materials.

Conjugated carbonyl compounds have become the most promising type of organic electrode materials for rechargeable Li-ion batteries because only they can achieve simultaneously high energy density, high cycling stability, and high power density. In this work, we have performed first-principles density functional theory (DFT) calculations to explore the fundamental rules of how the electronic structure and redox properties of a typical conjugated carbonyl compound, phenanthrenequinone (PQ), are modified by adjusting the heteroaromatic building blocks. Such a molecular design strategy allows for the improvement in discharge potential while the specific capacity remains nearly unchanged.

A density functional theory study on the thermodynamic and dynamic properties of anthraquinone analogue cathode materials for rechargeable lithium ion batteries.

Organic redox compounds have become the emerging electrode materials for rechargeable lithium ion batteries. The high electrochemical performance provides organic electrode materials with great opportunities to be applied in electric energy storage devices. Among the different types of organic materials, conjugated carbonyl compounds are the most promising type at present, because only they can simultaneously achieve, high energy density, high cycling stability, and high power density.

Theoretical Study of Plasmon-Enhanced Surface Catalytic Coupling Reactions of Aromatic Amines and Nitro Compounds.

Taking advantage of the unique capacity of surface plasmon resonance, plasmon-enhanced heterogeneous catalysis has recently come into focus as a promising technique for high performance light-energy conversion. This work performs a theoretical study on the reaction mechanism for conversions of p-aminothiophenol (PATP) and p-nitrothiophenol (PNTP) to aromatic azo species, p,p'-dimercaptoazobenzene (DMAB). In the absence of O2 or H2, the plasmon-driven photocatalysis mechanism (hot electron-hole reactions) is the major reaction channel.

Activation of oxygen on gold and silver nanoparticles assisted by surface plasmon resonances.

Surface plasmon resonances (SPRs) have been found to promote chemical reactions. In most oxidative chemical reactions oxygen molecules participate and understanding of the activation mechanism of oxygen molecules is highly important. For this purpose, we applied surface-enhanced Raman spectroscopy (SERS) to find out the mechanism of SPR-assisted activation of oxygen, by using p-aminothiophenol (PATP), which undergoes a SPR-assisted selective oxidation, as a probe molecule.

A DFT study on photoinduced surface catalytic coupling reactions on nanostructured silver: selective formation of azobenzene derivatives from para-substituted nitrobenzene and aniline.

We propose that aromatic nitro and amine compounds undergo photochemical reductive and oxidative coupling, respectively, to specifically produce azobenzene derivatives which exhibit characteristic Raman signals related to the azo group. A photoinduced charge transfer model is presented to explain the transformations observed in para-substituted ArNO(2) and ArNH(2) on nanostructured silver due to the surface plasmon resonance effect. Theoretical calculations show that the initial reaction takes place through excitation of an electron from the filled level of silver to the lowest unoccupied molecular orbital (LUMO) of an adsorbed ArNO(2) molecule, and from the highest occupied molecular orbital (HOMO) of an adsorbed ArNH(2) molecule to the unoccupied level of silver, during irradiation with visible light.

Surface-enhanced Raman spectroscopic study of p-aminothiophenol.

p-aminothiophenol (PATP) is an important molecule for surface-enhanced Raman spectroscopy (SERS). It can strongly interact with metallic SERS substrates and produce very strong SERS signals. It is a molecule that has often been used for mechanistic studies of the SERS mechanism as the photon-driven charge transfer (CT) mechanism is believed to be present for this molecule.

Photon-driven charge transfer and Herzberg-Teller vibronic coupling mechanism in surface-enhanced Raman scattering of p-aminothiophenol adsorbed on coinage metal surfaces: a density functional theory study.

The chemical enhancement effects in surface-enhanced Raman scattering of p-aminothiophenol (PATP, it is also called p-mercaptoaniline or p-aminobenzenthiol) adsorbed on coinage metal surfaces with single thiol end or trapped into metal-molecule-metal junctions with both thiol and amino groups have been studied by density functional theory (DFT). We focus on the influence of photon-driven charge transfer (PDCT) and chemical bonding interaction (ground-state charge transfer) on the intensity enhancement and frequency shift in the surface Raman spectra of PATP. For comparison, the electronic structures and transitions of free PATP are studied first.

Photon-driven charge transfer and photocatalysis of p-aminothiophenol in metal nanogaps: a DFT study of SERS.

When p-aminothiophenol (PATP) is used as a probe molecule and adsorbs on silver and gold nanogaps, a significant change of relative SERS intensities can be observed. Our DFT calculations show that surface photocatalytic coupling reactions yield a new surface species of p,p'-dimercaptoazobenzene (DMAB) causing the significant change in the SERS spectra.