Action at a distance: organic cation induced long range organization of interfacial water enhances hydrogen evolution and oxidation kinetics.

Engineering efficient electrode-electrolyte interfaces for the hydrogen evolution and oxidation reactions (HOR/HER) is central to the growing hydrogen economy. Existing descriptors for HOR/HER catalysts focused on species that could directly impact the immediate micro-environment of surface-mediated reactions, such as the binding energies of adsorbates. In this work, we demonstrate that bulky organic cations, such as tetrapropyl ammonium, are able to induce a long-range structure of interfacial water molecules and enhance the HOR/HER kinetics even though they are located outside the outer Helmholtz plane.

Engineered rare-earth nanomaterials for fluorescence imaging and therapy.

Early diagnosis and treatment are of great significance for hindering the progression of brain disease. The limited effects of available treatments and poor prognosis are currently the most pressing problems faced by clinicians and their patients. Therefore, developing new diagnosis and treatment programs for brain diseases is urgently needed.

Tetrahomo corona[4]arene-based spirophanes: synthesis, structure, and properties.

In contrast to a plethora of macrocyclic and cage compounds, spirophanes have remained largely unexplored. We report herein the construction, structure and properties of unprecedented tetrahomo corona[4]arene-based ditopic and tritopic macrocycles of spiro structures. Synthesis was conveniently achieved by means of an efficient SAr reaction from simple and commercially available starting materials.

PET recycling under mild conditions substituent-modulated intramolecular hydrolysis.

Catalytic depolymerization represents a promising approach for the closed-loop recycling of plastic wastes. Here, we report a knowledge-driven catalyst development for poly(ethylene terephthalate) (PET) recycling, which not only achieves more than 23-fold enhancement in specific activity but also reduces the alkali concentration by an order of magnitude compared with the conventional hydrolysis. Substituted binuclear zinc catalysts are developed to regulate biomimetic intramolecular PET hydrolysis.

Recent progress in flexible micro-pressure sensors for wearable health monitoring.

In recent years, flexible micro-pressure sensors have been used widely in wearable health monitoring applications due to their excellent flexibility, stretchability, non-invasiveness, comfort wearing and real-time detection. According to the working mechanism of the flexible micro-pressure sensor, it can be classified as piezoresistive, piezoelectric, capacitive and triboelectric types. Herein, an overview of flexible micro-pressure sensors for wearable health monitoring is presented.

Synthesis, characterization and performance of lignin carboxyl betaine zwitterionic surfactants for application in enhanced oil recovery.

The objective of this study was to synthesize lignin carboxyl betaine zwitterionic surfactants (LCBS) from alkali lignin through a three-step reaction involving epoxidation, amination, and quaternization. The synthesized LCBS were characterized using infrared spectroscopy (IR) and thermogravimetric (TG) analysis. To assess their potential for enhanced oil recovery (EOR), the physicochemical properties of the LCBS surfactants, such as surface tension, emulsification, temperature resistance, salt resistance, and interfacial properties, were evaluated using standard experimental methods for surfactants applied in oil displacement.

Nonspecific interactions between Cas12a and dsDNA located downstream of the PAM mediate target search and assist AsCas12a for DNA cleavage.

Cas12a is one of the most commonly used Cas proteins for genome editing and gene regulation. The first key step for Cas12a to fulfill its function is to search for its target among numerous nonspecific and off-target sites. Cas12a utilizes one-dimensional diffusion along the contour of dsDNA to efficiently search for its target.

Soft landing of polyatomic anions onto three-dimensional semiconductive and conductive substrates.

Soft landing of well-characterized polyoxometalate anions, PWO (WPOM) and PMoO (MoPOM), was carried out to explore the distribution of anions in the semiconducting 10 and 6 μm-long vertically aligned TiO nanotubes as well as 300 μm-long conductive vertically aligned carbon nanotubes (VACNTs). The distribution of soft-landed anions on the surfaces and their penetration into the nanotubes were studied using energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). We observe that soft landed anions generate microaggregates on the TiO nanotubes and only reside in the top 1.

Challenges in Recycling Spent Lithium-Ion Batteries: Spotlight on Polyvinylidene Fluoride Removal.

In the recycling of retired lithium-ion batteries (LIBs), the cathode materials containing valuable metals should be first separated from the current collector aluminum foil to decrease the difficulty and complexity in the subsequent metal extraction. However, strong the binding force of organic binder polyvinylidene fluoride (PVDF) prevents effective separation of cathode materials and Al foil, thus affecting metal recycling. This paper reviews the composition, property, function, and binding mechanism of PVDF, and elaborates on the separation technologies of cathode material and Al foil (e.

Single-atom catalysis enabled by high-energy metastable structures.

Owing to limited degrees of freedom, the active sites of stable single-atom catalyst (SAC) often have one structure that is energetically much lower than other local-minimum structures. Thus, the SAC adopts one lowest-energy structure (LES) with an overwhelmingly larger proportion than any other high-energy metastable structure (HEMS), and the LES is commonly assumed to be solely responsible for the catalytic performance of an SAC. Herein, we demonstrate with SACs anchored on CeO that the HEMS of an SAC, even though its proportion remains several orders of magnitude lower than the LES throughout the catalytic reaction, can dictate catalysis with extraordinary activity arising from its unique coordination environment and oxidation state.

Inherently chiral calixarenes by a catalytic enantioselective desymmetrizing cross-dehydrogenative coupling.

Under the catalysis of PdBr and a chiral phosphoramidite ligand, the upper-rim mono (2-bromoaroyl)-substituted calix[4]arene derivatives underwent a facile enantioselective desymmetrization reaction to afford 9-fluorene-embedded inherently chiral calixarenes in good yields with excellent enantioselectivities. The transannular dehydrogenative arene-arene coupling reaction proceeded most probably through an oxidative addition of the C-Br bond to a ligated palladium catalyst followed by a sequence of an enantioselective 1,5-palladium migration and an intramolecular C-H arylation sequence. This new family of inherently chiral calixarenes possesses unique chiroptical properties thanks to their highly rigid structure induced by the 9-fluorene segment.

Combined laser-induced breakdown spectroscopy and hyperspectral imaging with machine learning for the classification and identification of rice geographical origin.

With the events of fake and inferior rice and food products occurring frequently, how to establish a rapid and high accuracy monitoring method for rice food identification becomes an urgent problem. In this work, we investigate using combined laser-induced breakdown spectroscopy (LIBS) and hyperspectral imaging (HSI) with machine learning algorithms to identify the place of origin of rice production. Six geographical origin rice samples grown in different parts of China are selected and pretreated, and measured by the atomic emission spectra of LIBS and the reflection spectra of HSI, respectively.

Anode optimization strategies for aqueous zinc-ion batteries.

Zinc-ion batteries (ZIBs) have received much research attention due to their advantages of safety, non-toxicity, simple manufacture, and element abundance. Nevertheless, serious problems still remain for their anodes, such as dendrite development, corrosion, passivation, and the parasitic hydrogen evolution reaction due to their unique aqueous electrolyte system constituting the main issues that must be addressed, which are blocking the further advancement of anodes for Zn-ion batteries. Herein, we conduct an in-depth analysis of the problems that exist for the zinc anode, summarize the main failure types and mechanisms of the zinc anode, and review the main modification strategies for the anode from the three aspects of the electrolyte, anode surface, and anode host.

Achieving vibrational energies of diatomic systems with high quality by machine learning improved DFT method.

When using methods to obtain high-quality quantum behavior of molecules, it often involves a lot of trial-and-error work in algorithm design and parameter selection, which requires enormous time and computational resource costs. In the study of vibrational energies of diatomic molecules, we found that starting from a low-precision DFT model and then correcting the errors using the high-dimensional function modeling capabilities of machine learning, one can considerably reduce the computational burden and improve the prediction accuracy. Data-driven machine learning is able to capture subtle physical information that is missing from DFT approaches.

Enhanced stability of vanadium-doped LiNiCoMnO cathode materials for superior Li-ion batteries.

Lithium-manganese-based cathode materials have attracted much attention due to its high specific capacity, but the low initial coulomb efficiency, poor rate performance and voltage attenuation during cycling limit its application. In this work, LiNiCoMn V O samples ( = 0, 0.005, 0.

Fabricating sub-nanometer materials through cluster assembly.

The self-assembly of clusters provides a feasible approach for the bottom-up fabrication of functional materials with tailored properties. Sub-nanometer cluster assembly with a well-defined construction presents a precisely controllable structure and extraordinary properties, which provides an ideal model for the investigation of structures and properties at the molecular level. Non-covalent interactions between clusters may dominate the assembly behavior, appearing as tunable structures different from their nano-counterparts.

Rh-catalyzed regio-switchable cross-coupling of -difluorinated cyclopropanes with allylboronates to structurally diverse fluorinated dienes.

The control of linear/branched selectivity is one of the major focuses in transition-metal catalyzed allyl-allyl cross-coupling reactions, in which bond connection occurs at the terminal site of both the allyl fragments forming different types of 1,5-dienes. Herein, terminal/internal regioselectivity is investigated and found to be switchable in allyl-allyl cross-coupling reactions between -difluorinated cyclopropanes and allylboronates. The controlled terminal/internal regioselectivity arises from the fine-tuning of the rhodium catalytic system.

A wireless "Janus" soft gripper with multiple tactile sensors.

Biomimetic properties allow soft robots to complexly interact with the environment. As the bridge between the robot and the operating object, the gripping hand is an important organ for its connection with the outside world, which requires the ability to provide feedback from the grasped object, similar to the human sensory and nervous system. In this work, to cope with the difficulty of integrating complex sensing and communication systems into flexible soft grippers, we propose a GO/PI composite bilayer film-based gripper with two types of tactile sensors and a LC passive wireless transmission module to obtain the grip information and transmit it to the processor.

Non-contact friction energy dissipation hysteretic behavior on a graphite surface.

For non-contact friction, energy is usually dissipated through phonon excitation, Joule dissipation and van der Waals friction. Although some new dissipation mechanisms related to the quantum phenomenon have been discovered, the contribution of hysteretic behavior to non-contact friction energy dissipation is lacking in research. In this paper, the distance dependence of non-contact friction on the graphite surface is studied by using a quartz tuning fork with lateral vibration in the atmosphere.

Surface enrichment of Ir on the IrRu alloy for efficient and stable water oxidation catalysis in acid.

Inducing the surface enrichment of active noble metal can not only help to stabilize the catalyst but also modify the catalytic performance of the catalyst through electronic and geometric effects. Herein, we report the surface enrichment of Ir on IrRu alloy during the oxygen evolution reaction (OER). The surface enrichment of Ir was probed by high-resolution transmission electron microscopy (HRTEM), X-ray absorption spectroscopy (XAS), and electrochemical Cu stripping, leading to complementary characterizations of the dynamic reconstruction of the IrRu alloy during OER.

Low energy consumption fiber-type memristor array with integrated sensing-memory.

The increasing growth of electronic information science and technology has triggered the renaissance of the artificial sensory nervous system (SNS), which can emulate the response of organisms towards external stimuli with high efficiency. In traditional SNS, the sensor units and the memory units are separated, and therefore difficult to miniaturize and integrate. Here, we have incorporated the sensor unit and the memory unit into one system, taking advantage of the unique properties of the ion-gel system.

The smallest 4f-metalla-aromatic molecule of cyclo-PrB with Pr-B multiple bonds.

The concept of metalla-aromaticity proposed by Thorn-Hoffmann (. 1979, 3, 39) has been expanded to organometallic molecules of transition metals that have more than one independent electron-delocalized system. Lanthanides, with highly contracted 4f atomic orbitals, are rarely found in multiply aromatic systems.

Toward practical quantum embedding simulation of realistic chemical systems on near-term quantum computers.

Quantum computing has recently exhibited great potential in predicting chemical properties for various applications in drug discovery, material design, and catalyst optimization. Progress has been made in simulating small molecules, such as LiH and hydrogen chains of up to 12 qubits, by using quantum algorithms such as variational quantum eigensolver (VQE). Yet, originating from the limitations of the size and the fidelity of near-term quantum hardware, the accurate simulation of large realistic molecules remains a challenge.