MXene-Fiber Composite Membranes for Permeable and Biocompatible Skin-Interfaced Iontronic Mechanosensing.

Artificial ionic sensory systems, bridging the divide between biological systems and electronics, mimic human skin functions but face critical challenges with biocompatibility, comfort, signal stability, and simplifying packaging. Here, we present a simple and permeable skin-interfaced iontronic mechanosensing (SIIM) architecture that integrates human skin as natural ionic material and hierarchically porous MXene-fiber composite membranes as sensing electrodes. The SIIM system eliminates complex ionic material design and multilayer matrix, exhibiting ultrahigh pressure sensitivities (5.4 kPa-1, <75 Pa), a low detection limit (6 Pa), excellent output stability along with high permeability to minimize the impact of sweating on sensing. The noncytotoxic nature of SIIM electrodes ensures excellent biocompatibility (>97% cell coincubational viability), facilitating long-term wearability and high biosafety. Furthermore, the scalable SIIM configuration integrated with matrix smart gloves, effectively monitors human physical movements. This SIIM-based sensor with marked sensing capabilities, structural simplicity, and scalability, holds promising potential in diverse wearable applications.

Mechanochemically-based three-way approach for the synthesis of K-doped Cu-Fe/ZnO-Al2O3 catalysts for converting CO2 to oxygenates.

Three ball-milling methodologies were developed to synthesize bespoke multi-metallic K-doped Cu-Fe/ZnO-Al2O3 catalysts for the hydrogenation of carbon dioxide. The catalytic performance of the catalysts was benchmarked against their solution-based counterparts. The catalysts synthesized by ball milling are greener, showing smaller particles, with different selectivity towards oxygenate products.

Substrate-directed regioselective alkene functionalizations of (E)-ß,γ-unsaturated carboxylic acids.

A carboxylate-directed regioselective Heck-type alkenylation and alkenylative lactonization of (E)-ß,γ-unsaturated carboxylic acids by simply substrate control is reported. (E)- and (Z)-alkenyl bromides reacted to give energetically more favorable palladacyles, allowing access to fully stereocontrolled conjugated 1,3-dienes and alkenyled γ-lactones. Mechanistic studies suggest that excellent regioselectivity may be strongly influenced by the steric factors of reactants involved in the palladacycle intermediates.

Unassisted photoelectrochemical CO2-to-liquid fuel splitting over 12% solar conversion efficiency.

The increasing need to control anthropogenic CO2 emissions and conversion to fuels features the necessity for innovative solutions, one of which is photoelectrochemical system. This approach, capable of yielding gaseous production progressively, is facing challenges for liquid fuels generation due to optical, electrical, and catalytic properties. This study employs a standalone photoelectrochemical setup, in which InGaP/GaAs/Ge photoanode is integrated with tin-modified bismuth oxide cathode to convert CO2 into liquid formic acid. In unassisted two-electrode assembly, setup exemplifies its operational durability for 100 h, during which it maintains an average Faradaic efficiency of 88% with 17.3 mmol L-1 h-1 of yield, thereby excelling in average solar-to-fuel conversion efficiency at 12% with 60% of electrical energy efficiency under one sun illumination. This significant performance is further associated with metal-semiconductor interface formation between tin and bismuth oxide, which bridges electronic structures and generates an electric field at their interfaces. This study outperforms conventional solar-driven systems in operational durability and liquid fuel production.

Homogeneous Catalysis in N-formylation/N-methylation Utilizing Carbon Dioxide as the C1 Source.

The growing emphasis on sustainable chemistry has driven research into utilizing carbon dioxide (CO2) as a nontoxic, abundant, and cost-effective C1 building block. CO2 offers a promising avenue for direct conversion into valuable chemicals ranging from fuels to pharmaceuticals. This review focuses on the utilization of CO2 for reductive N-formylation/N-methylation reactions of various amines, providing advantages over conventional methods involving toxic CO and other methylating reagents. The approach employs readily available reductants such as silane, borane reagents, and hydrogen (H2). The discussion encompasses recent developments in transition metal and organocatalyst systems for these reactions, highlighting mechanistic interpretations and factors influencing product selectivity.

Electrocatalytic Hydrogen Generation by Ni-PN3P Pincer Complexes: Role of Phosphorus Substituents in Tuning the Reactivity.

Electrocatalytic hydrogen evolution reaction (eHER) is crucial in addressing the growing global energy demand. Although nickel-pincer-based molecular complexes, varying in donor atoms, were studied previously for eHER, the impact of variations in the substituents attached to the donor atoms was not investigated. Herein, three air-stable R1PN3PR2-based NiII-pincer complexes [R1=R2=Ph2 (7); R1=R2=tBu2 (9); R1= tBu2, R2=Ph2 (10)], varying solely in P-substituents, were studied in acetonitrile. While the redox potentials for NiII/I and NiI/0 couples underwent anodic shifts by ~100 mV upon progressively substituting tert-butyl by phenyl groups on each P-atom, the corresponding eHER reactivity with organic acids (acetic acid,  p-toluenesulfonic acid and trifluoromethanesulfonic acid) of different strengths followed different trends; likely influenced by the pKa of intermediate metal-hydride (M-H) species [pKa(M-H9) > pKa(M-H10) > pKa(M-H7)]. Depending on the acid strength, different oxidation states of the metal were activated to promote eHER. The catalytic rates for 9, 10, and 7 were calculated to be 85 s-1, 77 s-1 and 95 s-1 with Faradaic efficiencies of 88.5 ± 2%, 66.1 ± 1.4%, and 91.7 ± 1.5% respectively, in acetic acid. Electrochemical data supported by theoretical results reinforce a significant electronic influence of the anchoring P-substituents on the activity of these complexes.

Balancing Pd-H Interactions: Thiolate-Protected Palladium Nanoclusters for Robust and Rapid Hydrogen Gas Sensing.

The transition toward hydrogen gas (H2) as an eco-friendly and renewable energy source necessitates advanced safety technologies, particularly robust sensors for H2 leak detection and concentration monitoring. Although palladium (Pd)-based materials are preferred for their strong H2 affinity, intense palladium-hydrogen (Pd-H) interactions lead to phase transitions to palladium hydride (PdHx), compromising sensors' durability and detection speeds after multiple uses. In response, this study introduces a high-performance H2 sensor designed from thiolate-protected Pd nanoclusters (Pd8SR16), which leverages the synergistic effect between the metal and protective ligands to form an intermediate palladium-hydrogen-sulfur (Pd-H-S) state during H2 adsorption. Striking a balance, it preserves Pd-H binding affinity while preventing excessive interaction, thus lowering the energy required for H2 desorption. The dynamic adsorption-dissociation-recombination-desorption process is efficiently and highly reversible with Pd8SR16, ensuring robust and rapid H2 sensing at parts per million (ppm). The Pd8SR16-based sensor demonstrates exceptional stability (50 cycles; 0.11% standard deviation in response), prompt response/recovery (t90 = 0.95 s/6 s), low limit of detection (LoD, 1 ppm), and ambient temperature operability, ranking it among the most sensitive Pd-based H2 sensors. Furthermore, a multifunctional prototype demonstrates the practicality of real-world gas sensing using ligand-protected metal nanoclusters.

Solar-Powered Gram-Scale Ammonia Production from Nitrate.

The photoelectrochemical (PEC) method has the potential to be an attractive route for converting and storing solar energy as chemical bonds. In this study, a maximum NH3 production yield of 1.01 g L-1 with a solar-to-ammonia conversion efficiency of 8.17% through the photovoltaic electrocatalytic (PV-EC) nitrate (NO3 -) reduction reaction (NO3 -RR) is achieved, using silicon heterojunction solar cell technology. Additionally, the effect of tuning the operation potential of the PV-EC system and its influence on product selectivity are systematically investigated. By using this unique external resistance tuning approach in the PV-EC system, ammonia production through nitrate reduction performance from 96 to 360 mg L-1 is enhanced, a four-fold increase. Furthermore, the NH3 is extracted as NH4Cl powder using acid stripping, which is essential for storing chemical energy. This work demonstrates the possibility of tuning product selectivity in PV-EC systems, with prospects toward pilot scale on value-added product synthesis.

Postoperative prognostic nutrition index predicts survival in patients with small bowel adenocarcinoma after surgical resection.

BACKGROUND: Surgical resection (SR) is the main treatment for small bowel adenocarcinoma (SBA), but it increases metabolic demand, systemic inflammation, and digestive dysfunction, resulting in major impacts on the postoperative outcomes of patients. In this study, we aimed to investigate the role of the postoperative prognostic nutritional index (PNI), a surrogate marker of inflammation and nutrition, in patients with SBA after resection. METHODS: From June 2014 to March 2022, 44 consecutive patients who underwent SR for SBA in Taipei Veterans General Hospital were retrospectively reviewed. Factors associated with survival including PNI were analyzed. RESULTS: PNI decreased in patients after SR for SBA (median change: -1.82), particularly in those who underwent Whipple operation or developed postoperative pancreatic fistula. Postoperative PNI <45.2 best predicted overall survival (OS) (area under the receiver operating characteristic curve [AUROC]: 0.826, p = 0.001). Patients with lower postoperative PNI had significantly worse OS compared to those with higher postoperative values (median OS: 19.3 months vs not reached, p < 0.001). Low postoperative PNI (hazard ratio [HR]: 11.404, p = 0.002), tumoral lymphovascular invasion (HR: 8.023, p = 0.012), and adjuvant chemotherapy (HR: 0.055, p = 0.002) were independent risk factors for OS. Postoperative PNI also significantly predicted recurrence-free survival independent of lymphovascular invasion and adjuvant chemotherapy (HR: 6.705, p = 0.001). CONCLUSION: PNI commonly decreases in patients with SBA who undergo Whipple surgery or develop postoperative pancreatic fistula. Postoperative PNI independently predicts survival and may serve as a clinical marker to optimize patient outcomes.

Ligand-Dominated Activation of CO2 and CS2 by the Putative Nickel Phosphiniminato Intermediates.

Room-temperature photoactivation of the first- and second-generation PN3P-pincer nickel azido complexes 1a and 1b in the presence of CO2 or CS2 afforded N-bound carbamates, dithiocarbamates, and isothiocyanates, providing insights into CO2 and CS2 activation and demonstrating how a seemingly small difference in the ligand structure significantly influences the reactivity. Theoretical calculations disclosed that the charge of the phosphorus atom plays a critical role in determining the nitrogen atom transfer to form a plausible nickel phosphiniminato intermediate.

Gray mesoporous SnO2 catalyst for CO2 electroreduction with high partial current density and formate selectivity.

The mesoporous metal oxide semiconductors exhibit unique chemical and physical characteristics, making them highly desirable for catalysis, electrochemistry, energy conversion, and energy storage applications. Here, we report the facial fabrication of mesoporous gray SnO2 (MGS) electrocatalysts employing an evaporation-induced co-assembly (EICA) approach, utilizing poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymers Pluronic P123 (PEO-PPO-PEO) triblock copolymer as a template for electrochemical CO2 reduction reaction (eCO2RR). By sustaining the co-assembly conditions and utilizing a thermal treatment technique based on carbon, gray mesoporous SnO2 materials with a high density of active sites and oxygen vacancies can be constructed. The MGS materials were employed in eCO2RR in a flow cell type, which exhibits excellent catalytic activity and selectivity toward formate with a high partial current density of -234 mA cm-2 and Faradaic efficiency (FE) of 93.60 % at -1.3 V vs. reversible hydrogen electrode (RHE). Interestingly, the mesoporous SnO2 with a 1.5 wt% ratio of Sn precursor to P123 surfactant (MS-1.5@350N-400A) electrode exhibits a high level of Faradaic efficiency (FE) of (98%) at a low overpotential of -0.6 VRHE, which is a seldom recorded performance for similar systems. A stable FE of 96 ± 1% was observed in the range of -0.6 to -1.2 VRHE, which is the result of a large surface area (184 m2/g) and a high number of active sites and oxygen vacancies within the mesostructured framework.

Leveraging the Stereochemical Complexity of Octahedral Diastereomeric-at-Metal Catalysts to Unlock Regio-, Diastereo-, and Enantioselectivity in Alcohol-Mediated C-C Couplings via Hydrogen Transfer.

Experimental and computational studies illuminating the factors that guide metal-centered stereogenicity and, therefrom, selectivity in transfer hydrogenative carbonyl additions of alcohol proelectrophiles catalyzed by chiral-at-metal-and-ligand octahedral d6 metal ions, iridium(III) and ruthenium(II), are described. To augment or invert regio-, diastereo-, and enantioselectivity, predominantly one from among as many as 15 diastereomeric-at-metal complexes is required. For iridium(III) catalysts, cyclometalation assists in defining the metal stereocenter, and for ruthenium(II) catalysts, iodide counterions play a key role. Whereas classical strategies to promote selectivity in metal catalysis aim for high-symmetry transition states, well-defined low-symmetry transition states can unlock selectivities that are otherwise difficult to achieve or inaccessible.

Efficient and chemoselective imine synthesis catalyzed by a well-defined PN3-manganese(II) pincer system.

The highly efficient reductive amination of aldehydes with ammonia (NH3) and hydrogen (H2) to form secondary imines is described, as well as the dehydrogenative homocoupling of benzyl amines. Using an air-stable, well-defined PN3-manganese(II) pincer complex as a catalyst precursor, various aldehydes are easily converted directly into secondary imines using NH3 as a nitrogen source under H2 in a one-pot reaction. Importantly, the same catalyst facilitates the dehydrogenative homocoupling of various benzylamines, exclusively forming imine products. These reactions are conducted under very mild conditions, without the addition of any additives, yielding excellent selectivities and high yields of secondary imines in a green manner by minimizing wastes.

Post-Synthetic Ensembling Design of Hierarchically Ordered FAU-type Zeolite Frameworks for Vacuum Gas Oil Hydrocracking.

Zeolites hold importance as catalysts and membranes across numerous industrial processes that produce most of the world's fuels and chemicals. In zeolite catalysis, the rate of molecular diffusion inside the micropore channels defines the catalyst's longevity and selectivity, thereby influencing the catalytic efficiency. Decreasing the diffusion pathlengths of zeolites to the nanoscopic level by fabricating well-organized hierarchically porous architecture can efficiently overcome their intrinsic mass-transfer limitations without losing hydrothermal stability. We report a rational post-synthetic design for synthesizing hierarchically ordered FAU-type zeolites exhibiting 2D-hexagonal (P6mm) and 3D-cubic (Ia 3 ‾ ${\bar{3}}$ d) mesopore channels. The synthesis involves methodical incision of the parent zeolite into unit-cell level zeolitic fragments by in situ generated base and bulky surfactants. The micellar ensembles formed by these surfactant-zeolite interactions are subsequently reorganized into various ordered mesophases by tuning the micellar curvature with ion-specific interactions (Hofmeister effect). Unlike conventional crystallization, which offers poor control over mesophase formation due to kinetic constraints, crystalline mesostructures can be developed under dilute, mild alkaline conditions by controlled reassembly. The prepared zeolites with nanometric diffusion pathlengths have demonstrated excellent yields of naphtha and middle-distillates in vacuum gas oil hydrocracking with decreased coke deposition.

Organocatalyzed Enantioselective [2 + 2] Cycloaddition of C,N-Cyclic Ketimines and Allenoates.

We report a novel enantioselective and regioselective [2 + 2] cycloaddition of allenoate and C,N-cyclic ketimine catalyzed by a quinidine derivative. The methodology enables the synthesis of fused tricyclic azetidines with a quaternary stereogenic center exhibiting high enantioselectivities. The broad range of substrates demonstrates the generality of the protocol, and the resulting functional products can be easily converted to a variety of valuable synthons. To elucidate the plausible reaction mechanism and how the catalyst affects absolute stereocontrol over the products, we conducted the corresponding density functional theory (DFT) calculations.

Nanosynthesis and Characterization of Cu1.8Se0.6S0.4 as a Potential Cathode for Magnesium Battery Applications.

Copper selenide (Cu-Se) and copper sulfide (Cu-S) are promising cathodes for magnesium-ion batteries. However, the low electronic conductivity of Cu-Se system results in a poor rate capability and unsatisfactory cycling performance. Mg-ion batteries based on the Cu-S cathode exhibited large kinetic barriers during the recharging process owing to the presence of polysulfide species. This work attempts to circumvent this dilemma by doping Cu1.8Se by sulfur, which replaces the selenium in the CuSe lattice to form Cu1.8Se0.6S0.4 nanocrystalline powder. The presence of sulfur will increase the electronic conductivity, and the presence of selenium will mitigate the effect of polysulfide species that hinder the kinetics of Mg2+. Herein, a Cu1.8Se0.6S0.4 nanocrystalline powder was synthesized by the solid-state reaction, yielding a highly pure and stoichiometric powder. The crystallographic structure of the nanopowder and the conversion-type storage mechanism have been attested via ex situ X-ray diffraction and energy-dispersive X-ray analysis. The nanocrystalline feature of Cu1.8Se0.6S0.4 was demonstrated by high-resolution transmission electron microscopy. An apparent surface morphology change during the charging/discharging process has been visualized by a field emission scanning electron microscope. Diffuse reflectance spectroscopy has discussed the variation of the band gap during charging and discharging. The full Mg/Cu1.8Se0.6S0.4 cells presented an initial discharge capacity of 387.99 mAh g-1 at a current density of 0.02 mA cm-2; moreover, they show moderate diffusion kinetics with DMg2+ ≈ 10-15 cm-2 s-1.

Perovskite-Based X-ray Detectors.

X-ray detection has widespread applications in medical diagnosis, non-destructive industrial radiography and safety inspection, and especially, medical diagnosis realized by medical X-ray detectors is presenting an increasing demand. Perovskite materials are excellent candidates for high-energy radiation detection based on their promising material properties such as excellent carrier transport capability and high effective atomic number. In this review paper, we introduce X-ray detectors using all kinds of halide perovskite materials along with various crystal structures and discuss their device performance in detail. Single-crystal perovskite was first fabricated as an active material for X-ray detectors, having excellent performance under X-ray illumination due to its superior photoelectric properties of X-ray attenuation with µm thickness. The X-ray detector based on inorganic perovskite shows good environmental stability and high X-ray sensitivity. Owing to anisotropic carrier transport capability, two-dimensional layered perovskites with a preferred orientation parallel to the substrate can effectively suppress the dark current of the device despite poor light response to X-rays, resulting in lower sensitivity for the device. Double perovskite applied for X-ray detectors shows better attenuation of X-rays due to the introduction of high-atomic-numbered elements. Additionally, its stable crystal structure can effectively lower the dark current of X-ray detectors. Environmentally friendly lead-free perovskite exhibits potential application in X-ray detectors by virtue of its high attenuation of X-rays. In the last section, we specifically introduce the up-scaling process technology for fabricating large-area and thick perovskite films for X-ray detectors, which is critical for the commercialization and mass production of perovskite-based X-ray detectors.

Revisiting the Activity Gap of Iridium Electrocatalysts for Acidic Water Oxidation.

Iridium electrocatalysts have been extensively studied for the acidic water oxidation reaction (2H2O → O2 + 4H+ + 4e-, also known as the oxygen evolution reaction, OER) in recent years. However, the activity of different iridium catalysts, such as amorphous, crystalline, and metallic ones, varies significantly, and there is no common explanation for the origin of this difference. Here four types of iridium catalysts were selected as models and characterized by various techniques. The redox behavior of iridium catalysts and oxidation of hydrogen peroxide (in the form of OOH-) were applied to in situ probe the adsorption energy of oxygen reaction intermediates (*OH, *O, and *OOH) on iridium catalysts under the OER conditions. Structure-activity analysis suggested that the more optimal and broader distribution of adsorption energies on metallic iridium (iridium black) and its good conductivity are the origin of its highest activity among the four different iridium catalysts.

Interfacial Reconstructed Layer Controls the Orientation of Monolayer Transition-Metal Dichalcogenides.

Growing continuous monolayer films of transition-metal dichalcogenides (TMDs) without the disruption of grain boundaries is essential to realize the full potential of these materials for future electronics and optoelectronics, but it remains a formidable challenge. It is generally believed that controlling the TMDs orientations on epitaxial substrates stems from matching the atomic registry, symmetry, and penetrable van der Waals forces. Interfacial reconstruction within the exceedingly narrow substrate-epilayer gap has been anticipated. However, its role in the growth mechanism has not been intensively investigated. Here, we report the experimental conformation of an interfacial reconstructed (IR) layer within the substrate-epilayer gap. Such an IR layer profoundly impacts the orientations of nucleating TMDs domains and, thus, affects the materials' properties. These findings provide deeper insights into the buried interface that could have profound implications for the development of TMD-based electronics and optoelectronics.