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Oxidative alkene functionalization reactions are a fundamental class of complexity‐building organic transformations. However, the majority of established approaches rely on electrophilic reagents that limit the diversity of groups that can be installed. Recent advances have established a new approach that instead relies on the transformation of alkenes into thianthrene‐derived cationic electrophiles. These linchpin intermediates can be generated selectively and undergo a diverse array of mechanistically distinct reactions with abundant nucleophiles. Taken together, this unlocks a suite of net oxidative alkene transformations that have been elusive using conventional strategies. This Minireview describes these advances and is organized around the three distinct synthons formally accessible from alkenes via thianthrenation: 1) alkenyl cations; 2) vicinal dications; 3) allyl cations. Throughout the Minireview, we illustrate how thianthrenium salts address key limitations endemic to classic alkene‐derived electrophiles and highlight the mechanistic origins of these distinctions wherever possible. [ABSTRACT FROM AUTHOR]

Although great efforts on the delicate construction of a built‐in electric field (BIEF) to modify the electronic properties of active sites have been conducted, the substantial impact of BIEF coupled with electrode potential on the electrochemical reactions has not been clearly investigated. Herein, we designed an alkaline hydrogen evolution reaction (HER) catalyst composed of heterogeneous Ru−CoP urchin arrays on carbon cloth (Ru−CoP/CC) with a strong BIEF with the guidance of density functional theory (DFT) calculations. Impressively, despite its unsatisfactory activity at 10 mA cm−2 (overpotential of 44 mV), Ru−CoP/CC exhibited better activity (357 mV) than the benchmark Pt/C catalyst (505 mV) at 1 A cm−2. Experimental and theoretical studies revealed that strong hydrogen adsorption on the interfacial Ru atoms created a high energy barrier for hydrogen desorption and spillover, resulting in unsatisfactory activity at low current densities. However, as the electrode potential became more negative (i.e. the current density increased), the barrier for hydrogen spillover from the interfacial Ru to the Co site, which had near‐zero hydrogen adsorption energy, significantly decreased, thus greatly accelerating the whole alkaline HER process. This explains why the activity of Ru−CoP is relatively susceptible to the electrode potential compared to Pt/C. [ABSTRACT FROM AUTHOR]

Fast charging technology for electric vehicles (EVs), offering rapid charging times similar to conventional vehicle refueling, holds promise but faces obstacles owing to kinetic issues within lithium‐ion batteries (LIBs). Specifically, the significance of cathode materials in fast charging has grown because Ni‐rich cathodes are employed to enhance the energy density of LIBs. Herein, the mechanism behind the loss of fast charging capability of Ni‐rich cathodes during extended cycling is investigated through a comparative analysis of Ni‐rich cathodes with different microstructures. The results revealed that microcracks and the resultant cathode deterioration significantly compromised the fast charging capability over extended cycling. When thick rocksalt impurity phases form throughout the particles owing to electrolyte infiltration via microcracks, the limited kinetics of Li+ ions create electrochemically unreactive areas under high‐current conditions, resulting in the loss of fast charging capability. Hence, preventing microcrack formation by tailoring microstructures is essential to ensure stability in fast charging capability. Understanding the relationship between microcracks and the loss of fast charging capability is essential for developing Ni‐rich cathodes that facilitate stable fast charging upon extended cycling, thereby promoting widespread EV adoption. [ABSTRACT FROM AUTHOR]

Even though grain boundaries (GBs) have been previously employed to increase the number of active catalytic sites or tune the binding energies of reaction intermediates for promoting electrocatalytic reactions, the effect of GBs on the tailoring of the local chemical environment on the catalyst surface has not been clarified thus far. In this study, a GBs‐enriched iridium (GB−Ir) was synthesized and examined for the alkaline hydrogen evolution reaction (HER). Operando Raman spectroscopy and density functional theory (DFT) calculations revealed that a local acid‐like environment with H3O+ intermediates was created in the GBs region owing to the electron‐enriched surface Ir atoms at the GBs. The H3O+ intermediates lowered the energy barrier for water dissociation and provided enough hydrogen proton to promote the generation of hydrogen spillover from the sites at the GBs to the sites away from the GBs, thus synergistically enhancing the hydrogen evolution activity. Notably, the GB−Ir catalyst exhibited a high alkaline HER activity (10 mV @ 10 mA cm−2, 20 mV dec−1). We believe that our findings will promote further research on GBs and the surface science of electrochemical reactions. [ABSTRACT FROM AUTHOR]

Simultaneous optimization of the energy level of water dissociation, hydrogen and hydroxide desorption is the key to achieving fast kinetics for the alkaline hydrogen evolution reaction (HER). Herein, the well‐dispersed Ru clusters on the surface of amorphous/crystalline CeO2‐δ (Ru/ac‐CeO2‐δ) is demonstrated to be an excellent electrocatalyst for significantly boosting the alkaline HER kinetics owing to the presence of unique oxygen vacancy (VO) and Ru Lewis acid–base pairs (LABPs). The representative Ru/ac‐CeO2‐δ exhibits an outstanding mass activity of 7180 mA mgRu−1 that is approximately 9 times higher than that of commercial Pt/C at the potential of −0.1 V (V vs RHE) and an extremely low overpotential of 21.2 mV at a geometric current density of 10 mA cm−2. Experimental and theoretical studies reveal that the VO as Lewis acid sites facilitate the adsorption of H2O and cleavage of H‐OH bonds, meanwhile, the weak Lewis basic Ru clusters favor for the hydrogen desorption. Importantly, the desorption of OH from VO sites is accelerated via a water‐assisted proton exchange pathway, and thus boost the kinetics of alkaline HER. This study sheds new light on the design of high‐efficiency electrocatalysts with LABPs for the enhanced alkaline HER. [ABSTRACT FROM AUTHOR]

Synergistic optimization of the elementary steps of water dissociation and hydrogen desorption for the hydrogen evolution reaction (HER) in alkaline media is a challenge. Herein, the Ru cluster anchored on a trace P‐doped defective TiO2 substrate (Ru/P‐TiO2) was synthesized as an electrocatalyst for the HER; it exhibited a commercial Pt/C‐like geometric activity and an excellent mass activity of 9984.3 mA mgRu−1 at −0.05 V vs. RHE, which is 34.3 and 18.7 times higher than that of Pt/C and Ru/TiO2, respectively. Experimental and theoretical studies indicated that using a rutile‐TiO2‐crystal‐phase substrate enhanced the HER activity more than the anatase phase. Rich surface oxygen vacancies on rutile‐TiO2 facilitated the adsorption and dissociation of water, while the partial substitution of Ti4+ with P5+ enhanced H2 generation by facilitating hydrogen spillover from the Ru site to the surface P site, synergistically enhancing the HER activity. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) is a key reaction for many electrochemical devices. To date, many OER electrocatalysts function well in alkaline media, but exhibit poor performances in neutral and acidic media, especially the acidic stability. Herein, sodium‐decorated amorphous/crystalline RuO2 with rich oxygen vacancies (a/c‐RuO2) was developed as a pH‐universal OER electrocatalyst. The a/c‐RuO2 shows remarkable resistance to acid corrosion and oxidation during OER, which leads to an extremely high catalytic stability, as confirmed by a negligible overpotential increase after continuously catalyzing OER for 60 h at pH=1. Besides, a/c‐RuO2 also exhibits superior OER activities to commercial RuO2 and most reported OER catalysts under all pH conditions. Theoretical calculations indicated that the introduction of Na dopant and oxygen vacancy in RuO2 weakens the adsorption strength of the OER intermediates by engineering the d‐band center, thereby lowering the energy barrier for OER. [ABSTRACT FROM AUTHOR]

Facilitating the dissociation of water and desorption of hydrogen are both crucial challenges for improving the hydrogen evolution reaction (HER) in alkaline media. Herein, we report the synthesis of heterostructure of Ru2P/WO3@NPC (N, P co‐doped carbon) by a simple hydrothermal reaction using ruthenium and tungsten salts as precursors, followed by pyrolyzing under an Ar atmosphere. The Ru2P/WO3@NPC electrocatalyst exhibits an outstanding HER activity with an overpotential of 15 mV at a current density of 10 mA cm−2 and excellent durability in a 1.0 M KOH solution, outperforming state‐of‐the‐art Pt/C and most reported electrocatalysts. Experimental results combined with density functional calculations reveal that the electron density redistribution in Ru2P/WO3@NPC is achieved by electron transfer from NPC to Ru2P/WO3 and from Ru2P to WO3, which directly promotes the dissociation of water on W sites in WO3 and desorption of hydrogen on Ru sites in Ru2P. [ABSTRACT FROM AUTHOR]

Abstract: Biocompatible nanoparticles based on a calcium analogue of Prussian blue were designed and synthesized to take advantage of their ability to penetrate the cell membrane in Staphylococcus aureus and to undergo selective ion exchange with intracellular iron to disrupt iron metabolism in such pathogenic bacteria for antibacterial applications. KCa(H2O)2[FeIII(CN)6]⋅H2O nanoparticles penetrate the bacterial cell membrane and sequester intracellular iron by ion exchange to form insoluble Prussian blue, thus inhibiting bacterial growth. [ABSTRACT FROM AUTHOR]

In this study, we proposed high-performance chemically regenerative redox fuel cells (CRRFCs) using NO3−/NO with a nitrogen-doped carbon-felt electrode and a chemical regeneration reaction of NO to NO3− via O2. The electrochemical cell using the nitrate reduction to NO at the cathode on the carbon felt and oxidation of H2 as a fuel at the anode showed a maximal power density of 730 mW cm−2 at 80 °C and twofold higher power density of 512 mW cm−2 at 0.8 V, than the target power density of 250 mW cm−2 at 0.8 V in the H2/O2 proton exchange membrane fuel cells (PEMFCs). During the operation of the CRRFCs with the chemical regeneration reactor for 30 days, the CRRFCs maintained 60 % of the initial performance with a regeneration efficiency of about 92.9 % and immediately returned to the initial value when supplied with fresh HNO3. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) has multifunctional roles as a gas signaling molecule in living systems. However, the efficient detection and imaging of H2S in live animals is very challenging. Herein, we report the first radioisotope-based immobilization technique for the detection, quantification, and in vivo imaging of endogenous H2S. Macrocyclic 64Cu complexes that instantly reacted with gaseous H2S to form insoluble 64CuS in a highly sensitive and selective manner were prepared. The H2S concentration in biological samples was measured by a thin-layer radiochromatography method. When 64Cu-cyclen was injected into mice, an elevated H2S concentration in the inflamed paw was clearly visualized and quantified by Cerenkov luminescence and positron emission tomography (PET) imaging. PET imaging was also able to pinpoint increased H2S levels in a millimeter-sized infarcted lesion of the rat heart. [ABSTRACT FROM AUTHOR]

High electrochemical reactivity is required for various energy and sensing applications of graphene grown by chemical vapor deposition (CVD). Herein, we report that heterogeneous electron transfer can be remarkably fast at CVD-grown graphene electrodes that are fabricated without using the conventional poly(methyl methacrylate) (PMMA) for graphene transfer from a growth substrate. We use nanogap voltammetry based on scanning electrochemical microscopy to obtain very high standard rate constants k0≥25 cms-1 for ferrocenemethanol oxidation at polystyrene-supported graphene. The rate constants are at least 2-3 orders of magnitude higher than those at PMMA-transferred graphene, which demonstrates an anomalously weak dependence of electron-transfer rates on the potential. Slow kinetics at PMMA-transferred graphene is attributed to the presence of residual PMMA. This unprecedentedly high reactivity of PMMA-free CVD-grown graphene electrodes is fundamentally and practically important. [ABSTRACT FROM AUTHOR]

Regulating competitive reaction pathways to direct the selectivity of electrochemical CO2 reduction reaction toward a desired product is crucial but remains challenging. Herein, switching product from HCOOH to CO is achieved by incorporating Sb element into the CuS, in which the Cu−S ionic bond is coupled with S−Sb covalent bond through bridging S atoms that elongates the Cu−S bond from 2.24 Å to 2.30 Å. Consequently, CuS with a shorter Cu−S bond exhibited a high selectivity for producing HCOOH, with a maximum Faradaic efficiency (FE) of 72 %. Conversely, Cu3SbS4 characterized by an elongated Cu−S bond exhibited the most pronounced production of CO with a maximum FE of 60 %. In situ spectroscopy combined with density functional theory calculations revealed that the altered Cu−S bond length and local coordination environment make the *HCOO binding energy weaker on Cu3SbS4 compared to that on CuS. Notably, a volcano‐shaped correlation between the Cu−S bond length and adsorption strength of *COOH indicates that Cu−S in Cu3SbS4 as double‐active sites facilitates the adsorption of *COOH, and thus results in the high selectivity of Cu3SbS4 toward CO. [ABSTRACT FROM AUTHOR]

Synergistic optimization of the elementary steps of water dissociation and hydrogen desorption for the hydrogen evolution reaction (HER) in alkaline media is a challenge. Herein, the Ru cluster anchored on a trace P‐doped defective TiO2 substrate (Ru/P‐TiO2) was synthesized as an electrocatalyst for the HER; it exhibited a commercial Pt/C‐like geometric activity and an excellent mass activity of 9984.3 mA mgRu−1 at −0.05 V vs. RHE, which is 34.3 and 18.7 times higher than that of Pt/C and Ru/TiO2, respectively. Experimental and theoretical studies indicated that using a rutile‐TiO2‐crystal‐phase substrate enhanced the HER activity more than the anatase phase. Rich surface oxygen vacancies on rutile‐TiO2 facilitated the adsorption and dissociation of water, while the partial substitution of Ti4+ with P5+ enhanced H2 generation by facilitating hydrogen spillover from the Ru site to the surface P site, synergistically enhancing the HER activity. [ABSTRACT FROM AUTHOR]