Manipulating OH−-Mediated Anode-Cathode Cross-Communication Toward Long-Life Aqueous Zinc-Vanadium Batteries

The anode-cathode interplay is an important but rarely considered factor that initiates the degradation of aqueous zinc ion batteries (AZIBs). Herein, to address the limited cyclability issue of V-based AZIBs, Al₂(SO₄)₃ is proposed as decent electrolyte additive to manipulate OH⁻-mediated cross-communication between Zn anode and NaV₃O₈ ⋅ 1.5H₂O (NVO) cathode. The hydrolysis of Al³⁺ creates a pH≈0.9 strong acidic environment, which unexpectedly prolongs the anode lifespan from 200 to 1000 h. Such impressive improvement is assigned to the alleviation of interfacial OH⁻ accumulation by Al³⁺ adsorption and solid electrolyte interphase formation. Accordingly, the strongly acidified electrolyte, associated with the sedated crossover of anodic OH⁻ toward NVO, remarkably mitigate its undesired dissolution and phase transition. The interrupted OH⁻-mediated communication between the two electrodes endows Zn||NVO batteries with superb cycling stability, at both low and high scan rates.     

Durable Electrocatalytic Reduction of Nitrate to Ammonia over Defective Pseudobrookite Fe2TiO5 Nanofibers with Abundant Oxygen Vacancies

We propose the pseudobrookite Fe₂TiO₅ nanofiber with abundant oxygen vacancies as a new electrocatalyst to ambiently reduce nitrate to ammonia. Such catalyst achieves a large NH₃ yield of 0.73 mmol h⁻¹ mg⁻¹_cat. and a high Faradaic Efficiency (FE) of 87.6 % in phosphate buffer saline solution with 0.1 M NaNO₃, which is lifted to 1.36 mmol h⁻¹ mg⁻¹_cat. and 96.06 % at −0.9 V vs. RHE for nitrite conversion to ammonia in 0.1 M NaNO₂. It also shows excellent electrochemical durability and structural stability. Theoretical calculation reveals the enhanced conductivity of this catalyst and an extremely low free energy of −0.28 eV for nitrate adsorption at the presence of vacant oxygen.     

Ultrasound-Directed Symmetry Breaking and Spin Filtering of Supramolecular Assemblies from only Achiral Building Blocks

Herein we describe the self-assembly of an achiral molecule into macroscopic helicity as well as the emergent chiral-selective spin-filtering effect. It was found that a benzene-1,3,5-tricarboxamide (BTA) motif with an aminopyridine group in each arm could coordinate with Ag^I and self-assemble into nanospheres. Upon sonication, symmetry breaking occurred and the nanospheres transferred into helical nanofibers with strong CD signals. Although the sign of the CD signals appeared randomly, it could be controlled by using the as-made chiral assemblies as a seed. Furthermore, it was found that the charge transport of the helical nanofibers was highly selective with a spin-polarization transport of up to 45 %, although the chiral nanofibers are composed exclusively from achiral building blocks. This work demonstrates symmetry breaking under sonication and the chiral-selective spin-filtering effect.     

Dynamic Lone Pair Expression as Chemical Bonding Origin of Giant Phonon Anharmonicity in Thermoelectric InTe

Loosely bonded (“rattling”) atoms with s² lone pair electrons are usually associated with strong anharmonicity and unexpectedly low thermal conductivity, yet their detailed correlation remains largely unknown. Here we resolve this correlation in thermoelectric InTe by combining chemical bonding analysis, inelastic X-ray and neutron scattering, and first principles phonon calculations. We successfully probe soft low-lying transverse phonons dominated by large In¹⁺ z-axis motions, and their giant anharmonicity. We show that the highly anharmonic phonons arise from the dynamic lone pair expression with unstable occupied antibonding states induced by the covalency between delocalized In¹⁺ 5s² lone pair electrons and Te 5p states. This work pinpoints the microscopic origin of strong anharmonicity driven by rattling atoms with stereochemical lone pair activity, important for designing efficient materials for thermoelectric energy conversion.     

Tuning Local Coordination Environments of Manganese Single-Atom Nanozymes with Multi-Enzyme Properties for Selective Colorimetric Biosensing

Single-atom nanozymes (SAzymes) are promising in next-generation nanozymes, nevertheless, how to rationally modulate the microenvironment of SAzymes with controllable multi-enzyme properties is still challenging. Herein, we systematically investigate the relationship between atomic configuration and multi-enzymatic performances. The constructed Mn_SA−N₃-coordinated SAzymes (Mn_SA−N₃−C) exhibits much more remarkable oxidase-, peroxidase-, and glutathione oxidase-like activities than that of Mn_SA−N₄−C. Based on experimental and theoretical results, these multi-enzyme-like behaviors are highly dependent on the coordination number of single atomic Mn sites by local charge polarization. As a consequence, a series of colorimetric biosensing platforms based on Mn_SA−N₃−C SAzymes is successfully built for specific recognition of biological molecules. These findings provide atomic-level insight into the microenvironment of nanozymes, promoting rational design of other demanding biocatalysts.     

Selective Preparation of Phosphorus Mononitride (P≡N) from Phosphinoazide and Reversible Oxidation to Phosphinonitrene

The interstellar candidate phosphorus mononitride PN, a metastable species, was generated through high-vacuum flash pyrolysis of (o-phenyldioxyl)phosphinoazide in cryogenic matrices. Although the PN stretching band was not directly detected because of its low infrared intensity and possible overlaps with other strong bands, o-benzoquinone, carbon monoxide, and cyclopentadienone as additional fragmentation products were clearly identified. Moreover, an elusive o-benzoquinone-PN complex formed when (o-phenyldioxyl)phosphinoazide was exposed to UV irradiation at λ=254 nm. Its recombination to (o-phenyldioxyl)-λ⁵-phosphinonitrile was observed upon irradiation with the light at λ=523 nm, which demonstrates for the first time the reactivity of PN towards an organic molecule. Energy profile computations at the B3LYP/def2-TZVP density functional theory level reveal a concerted mechanism. To provide further evidence, UV/Vis spectra of the precursor and the irradiation products were recorded and agree well with time-dependent DFT computations.     

Photo-Activated Circularly Polarized Luminescence Film Based on Aggregation-Induced Emission Copper(I) Cluster-Assembled Materials

In this study, a pair of chiral copper(I) cluster-assembled materials (R/S- 2 ) was prepared, exhibiting unique photo-response characteristics with a concentration-wavelength correlation property in DMSO solution. By the combination of R/S- 2 with a polymethyl methacrylate (PMMA) matrix, the first photo-activated circularly polarized luminescence (CPL) film was developed, the CPL signal (g_lum=9×10⁻³) of which could be induced by UV light irradiation. Moreover, the film exhibited a reversible photo-response and extremely good fatigue resistance. Mechanism study revealed that the photo-response properties of the R/S- 2 solution and film are attributed to the aggregation-induced emission (AIE) characteristics of R/S- 2 and a photo-induced deoxygenation process. This study enriches the types of luminescent cluster-assembled molecules and provides a new strategy for the construction of metal cluster-based stimuli-responsive composite materials.     

Aggregation-Induced Emission by Molecular Design: A Route to High-Performance Light-Emitting Electrochemical Cells

The emission efficiency of organic semiconductors (OSCs) often suffers from aggregation caused quenching (ACQ). An elegant solution is aggregation-induced emission (AIE), which constitutes the design of the OSC so that its morphology inhibits quenching π–π interactions and non-radiative motional deactivation. The light-emitting electrochemical cell (LEC) can be sustainably fabricated, but its function depends on motion of bulky ions in proximity of the OSC. It is therefore questionable whether the AIE morphology can be retained during LEC operation. Here, we synthesize two structurally similar OSCs, which are distinguished by that 1 features ACQ while 2 delivers AIE. Interestingly, we find that the AIE-LEC significantly outperforms the ACQ-LEC. We rationalize our finding by showing that the AIE morphology remains intact during LEC operation, and that it can feature appropriately sized free-volume voids for facile ion transport and suppressed non-radiative excitonic deactivation.     

Ethene-1,1-disulfonyl Difluoride (EDSF) for SuFEx Click Chemistry: Synthesis of SuFExable 1,1-Bissulfonylfluoride Substituted Cyclobutene Hubs

We present the synthesis of 1,1-bis(fluorosulfonyl)-2-(pyridin-1-ium-1-yl)ethan-1-ide, a bench-stable precursor to ethene-1,1-disulfonyl difluoride (EDSF). The novel SuFEx reagent, EDSF, is demonstrated in the preparation of 26 unique 1,1-bissulfonylfluoride substituted cyclobutenes via a cycloaddition reaction. The regioselective click cycloaddition reaction is rapid, straightforward, and highly efficient, enabling the generation of highly functionalized 4-membered ring (4MR) carbocycles. These carbocycles are valuable structural motifs found in numerous bioactive natural products and pharmaceutically relevant small molecules. Additionally, we showcase diversification of the novel cyclobutene cores through selective Cs₂CO₃-activated SuFEx click chemistry between a single S−F group and an aryl alcohol, yielding the corresponding sulfonate ester products with high efficiency. Finally, density functional theory calculations offer mechanistic insights about the reaction pathway.     

Enabling the Operation of Highly Compatible LiI-3-Hydroxypropionitrile Small-Molecule Solid-State Electrolytes in Lithium Metal Batteries via Stepped-Amorphization Strategy

Integrating the advantages of both inorganic ceramic and organic polymer solid-state electrolytes, small-molecule solid-state electrolytes represented by LiI-3-hydroxypropionitrile (LiI-HPN) inorganic–organic hybrid systems possess good interfacial compatibility and high modulus. However, their lack of intrinsic Li⁺ conduction ability hinders potential application in lithium metal batteries until now, despite containing LiI phase composition. Herein, inspired by evolution tendency of ionic conduction behaviors together with first-principles molecular dynamics simulations, we propose a stepped-amorphization strategy to break the Li⁺ conduction bottleneck of LiI-HPN. It involves three progressive steps of composition (LiI-content increasing), time (long-time standing), and temperature (high-temperature melting) regulations, to essentially construct a small-molecule-based composite solid-state electrolyte with intensified amorphous degree, which realizes efficient conversion from an I⁻ to Li⁺ conductor and improved conductivity. As a proof, the stepped-optimized LiI-HPN is successfully operated in lithium metal batteries cooperated with Li₄Ti₅O₁₂ cathode to deliver considerable compatibility and stability over 250 cycles. This work not only clarifies the ionic conduction mechanisms of LiI-HPN inorganic–organic hybrid systems, but also provides a reasonable strategy to broaden the application scenarios of highly compatible small-molecule solid-state electrolytes.