In this work, cyclic voltammetry, square wave voltammetry, and chronopotentiometry were employed to systematically investigate the electrochemical behavior of O[2-] in LiF-BeF2 (66.7: 33.3 mol%) (FLiBe) molten salt on a gold electrode. Comparative analysis demonstrated that square wave voltammetry is more suitable than cyclic voltammetry for studying the electrochemical behavior of O[2-]. The square wave voltammetry results confirmed that O[2-] is oxidized to O2, with the electrode reaction controlled by ion diffusion. chronopotentiometry confirmed that the electrochemical behavior of O[2-] obeyed the Sand law. The diffusion coefficient of O[2-] in FLiBe by chronopotentiometry followed Arrhenius' law. Then, a well-fitted linear relationship between O[2-] concentration and square wave voltammetry peak current density was established, enabling rapid determination and real-time monitoring of oxide content in an unknown FLiBe molten salt. Furthermore, the electrochemical deoxygenation of FLiBe was performed using the potentiostatic electrolysis technique, and a satisfactory removal efficiency of O[2-] was achieved. This study presents an in situ electrochemical quantitative analysis method to monitor the O[2-] concentration in FLiBe, overcoming the drawback of the long testing cycle in conventional chemical analysis. Meanwhile, this study provides new technical support for the deoxygenation and purification of the fuel salt in molten salt reactors.

Molten fluoride salts are critical heat carriers and fuel solvents for advanced molten salt reactors. Yet, their complex atomic interactions and composition-dependent structural evolution remain challenging to characterize over a wide range of temperatures and compositions. Here, we develop a highly transferable and accurate machine learning interatomic potential for the ternary LiF-BeF2-UF4 system, enabling large-scale molecular dynamics simulations with near-density functional theory accuracy across UF4 concentrations from 0 to 25 mol. %. Trained from ab initio molecular dynamics data via an active learning loop, this potential achieves low root-mean-square errors for energy and forces and exhibits excellent cross-concentration generalization. Using this model, we reveal that U4+ acts as a network modifier that competes for F- ligands and promotes the formation of an extended Be-F-U ionic network, which governs the macroscopic physicochemical properties. With increasing UF4 content, the formation of interconnected networks is found to be correlated with reduced ion mobility, lower thermal conductivity, and higher shear viscosity, suggesting a mechanistic link that awaits further quantitative validation. We further quantify the coordination environments, cage correlation lifetimes, cluster network evolution, ion diffusion activation energies, and thermophysical properties, establishing a clear composition-structure-property relationship at the atomic scale. This work provides a robust computational framework for fluoride fuel salts and offers mechanistic insights critical for the design and optimization of thorium-based molten salt reactor fuels. The developed deep potential is transferable, scalable, and expected to serve as a reliable tool for future multiscale studies of complex molten salt systems.

In this work, for the first time, hybrid membranes are successfully fabricated using 2D lanthanide metal-organic frameworks, PVDF-HFP (poly(vinylidene fluoride-co-hexafluoropropylene)), and metal salts (Li[+] and Na[+]). These hybrid membranes show a layered structure with excellent thermal stability and good mechanical strength. Ionic conductivities in the order of 10[-4] S cm[-1] are achieved for both Li[+] and Na[+] ions in these membranes. Additionally, the overall ion-conduction behaviour is correlated with the structural characteristics to predict the ion-conduction pathway and mechanism.

Membrane distillation-crystallization (MD-MCr) has emerged as a promising route for recovering valuable salts and water from brine and wastewater streams; however, its industrial implementation depends critically on membrane robustness, scalability, and material chemistry, which together govern process selectivity and durability. Here, we employ constant chemical potential molecular dynamics (CμMD) simulations to probe the interfacial behavior of LiCl solutions in contact with polyvinylidene fluoride (PVDF) and polypropylene (PP) membranes across a range of concentrations. Concentration profiles reveal pronounced ion structuring near both polymer surfaces. PVDF exhibits gradual ion accumulation with increasing concentration, whereas PP displays distinct adsorption peaks only at higher salinity. Despite the absence of preferential ion adsorption and the resulting near-neutral interfacial charge distribution, adsorption isotherms and free-energy profiles reveal stronger affinity and greater interfacial heterogeneity for PVDF, arising from its polar fluorine groups. The deeper adsorption free-energy minima observed for PVDF indicate stronger ion-polymer interactions, consistent with the experimentally observed tendency of fluoropolymers to undergo wetting and structural modification upon prolonged exposure to lithium salts. These simulations, therefore, capture the earliest molecular-scale processes preceding membrane degradation. By linking polymer polarity, ion adsorption, and interfacial structuring, this work provides a molecular framework for understanding and tailoring ion-polymer interactions in membranes designed for lithium recovery and high-salinity separations.

Phosphorus tailings (PTs) accumulate in large quantities and demand safe, scalable management. Targeting the water-soluble hazardous constituents in PTs (phosphate, fluoride, and heavy metals), we applied targeted solidification/stabilization (S/S). PTs-based soils were implemented using FeSO4 and polyaluminum salts (PAC/PAS) combined with humic acid and organic wastes. An integrated assessment covered physicochemical properties, nutrient release, plant performance, microbial communities, and ecological functions. A 4% targeted stabilizer achieved immobilization efficiencies of 95.1% for fluoride and 88.24% for phosphate. With PTs >85.25% and 40-day ambient incubation, co-amended substrates outperformed PTs controls in structural attributes, pH buffering, EC management, and controlled nutrient release. Notably, in PPS and PHS treatments, combining humic acid with organic manures elevated pak-choi germination to 93%, increased microbial diversity, and enriched plant growth-promoting functions, demonstrating strong synergy with the targeted S/S regime and improving the ecological adaptability and sustainability of PTs-based soils. Collectively, these results establish both a theoretical basis and a practical pathway for the ecological valorization of PTs.

Plasma electrolytic oxidation (PEO) is an effective method for developing protective conversion coatings on magnesium and its alloys. The efficiency of this process is governed by several factors, including electrical parameters and electrolyte composition. Typically, PEO has been performed in alkaline silicate or phosphate solutions, often enriched with simple fluoride ions (F[-]) to improve the mechanical and anticorrosive properties of the resulting layers. Recently, the positive impact of complex fluoride ions (such as ZrF6[2-], TiF6[2-], SiF6[2-], AlF6[3-] and PF6[-]) on the properties of conversion coatings on magnesium substrates has been shown. This review analyzes how these complex precursors influence the phase composition, morphology, and corrosion resistance of coatings. Furthermore, these parameters are compared with those obtained by using electrolytes composed of a mixture of simple fluorides and additional constituents that provide the incorporation of the appropriate elements into the coating structure (phosphorus, silicon, zirconium, titanium, or aluminum). It was indicated that when using complex fluoride salts, an important aspect is the stability of the electrolyte, which depends on pH and the presence of stabilizing additives. Ensuring that the decomposition of the complex fluoride occurs during the PEO process increases the amount of fluorine incorporated into the layers formed, leading to the formation of a coating with enhanced properties.

Per- or polyfluoroalkyl substances (PFAS) represent a large family of chemicals, widely used due to their outstanding properties. However, also known as "Forever Chemicals", they are raising attention due to high health and environmental risks. In last years, the elimination, degradation, or recycling of PFAS has become essential. In this work, the degradation of a perfluorosulfonic acid polymer, Nafion, composed of a poly(tetrafluoroethylene) backbone with perfluoroether side chains terminated by sulfonic acid groups, is studied. More precisely, the mechanochemical degradation, previously described for linear fluoropolymers, is reported on branched PFSA polymers in the presence of various activators (such as (pyro)phosphates, 1,8-Diazabicyclo [5.4.0]undec-7-ene (DBU), 1,5,7-Triazabicyclo [4.4.0]dec-5-ene(TBD), KOH) at room temperature. Recovered products were characterized over time by nuclear magnetic resonance and Fourier transformation infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, and liquid chromatography-mass spectrometry in order to both identify the released products and suggest a degradation pathway. The use of potassium hydroxide, although resulting in a moderate potassium fluoride yield, allowed the determination of fragments produced during the degradation mechanism, while others were ineffective. Phosphate salts have been revealed to be the best candidates enabling the mineralization of PFSA, yielding valuable products and a good fluorine recovery for a further circular economy.

Appel halogenation reactions are widely used to convert alcohols to alkyl halides but are not suitable to prepare alkyl fluorides because fluoride is sequestered as a difluorophosphorane. In this work, we introduce bench-stable neopentoxyphosphonium salts to solve this enduring challenge. With these reagents, various alcohols undergo fluorination with potassium fluoride under hydrogen bonding phase-transfer catalysis, a manifold offering a pathway to enantioselective fluorination of alcohols. Mechanistically, a neopentoxyfluorophosphorane is formed, which undergoes reversible exchange with the alcohol substrate in preference to difluorophosphorane formation. The catalyst assists with potassium fluoride solubilization and with phosphorus-fluorine bond dissociation, leading to the alkoxyphosphonium fluoride ion pair undergoing stereoinvertive fluorination. Turnover results from stronger binding of the catalyst to fluoride than phosphine oxide, the by-product of the reaction, which is recyclable as starting material for the synthesis of the phosphonium reagents.

Carbocations are among the most versatile reactive intermediates in organic synthesis. Serving as the electrophilic linchpin for fundamental transformations such as SN1 substitutions, Friedel-Crafts alkylations, Ritter reactions, polyene cyclization cascades, and many other transformations, they provide a powerful means to construct C-C and C-heteroatom bonds. Classically, however, access to these high-energy intermediates has been restricted to the ionization of reactive precursors ─ alkyl halides or sulfonates ─ often requiring harsh thermal, acidic and/or solvolytic conditions that limit functional group tolerance and favor competitive elimination. The ability to generate carbocations directly from ubiquitous, inert C(sp3)-H bonds has long been considered a holy grail of chemical synthesis. Otherwise known as hydride abstraction, it is hampered by a steep thermodynamic barrier; the heterolytic cleavage of a C-H bond is significantly more endergonic than its homolytic counterpart. This Account describes our laboratory's development of a catalytic platform that overcomes this thermodynamic challenge to enable a general formal hydride abstraction. We reasoned that the high-energy process of removing a hydride (H-) in a single step could be decoupled into two lower-energy, kinetically accessible steps mediated by visible-light photoredox catalysis: Hydrogen Atom Transfer (HAT) followed by oxidative Radical-Polar Crossover (RPC), or [HAT+RPC]. By utilizing a photocatalyst to orchestrate both the generation of a carbon-centered radical and its subsequent oxidation to a carbocation, we have unlocked a manifold for SN1-type reactivity on simple hydrocarbons under mild conditions. We trace the evolution of this concept from its genesis in nucleophilic C-H fluorination, where we utilized tert-butyl peroxybenzoate (TBPB) to engage the fluoride anion ─ a classically difficult coupling partner in homolytic transformations. Building on this success, we expanded the platform to oxygen nucleophiles, establishing a photochemical alternative to the Williamson ether synthesis that avoids the elimination side-reactions typical of strong bases. We further detail the critical reagent evolution necessitated by nitrogen nucleophiles, where the introduction of N-alkoxypyridinium salts solved the problem of competitive byproduct nucleophilicity, enabling the synthesis of N-benzyl azoles. Finally, we discuss our deep mechanistic interrogation of C-H sulfonamidation, where the identification and suppression of a parasitic proton-coupled electron transfer (PCET) pathway proved essential for catalytic efficiency. Collectively, these studies demonstrate that with the correct polarity-inversion machinery, C-H bonds can be viewed not merely as radical precursors, but as latent carbocations ready to engage in the full spectrum of polar reactivity.

Due to their exceptional stability, only few transition metal catalysts are capable of activating C─F bonds for C-C-coupling reactions, usually under harsh conditions or with highly reactive nucleophiles. We herein report that a methyl naphthyl (MeNAP) palladium trifluoroacetate/[t]BuBrettPhos catalyst with lithium bis(trimethylsilyl)amide (LiHMDS) as the base enables α-arylations of in situ generated enolates with non-activated aryl fluorides. The reaction proceeds under mild conditions at room temperature and extends to ketone, ester, nitrile, and even amide enolates. DFT calculations reveal that the coordination of lithium salts to the fluorine atom decisively facilitates the insertion of Pd into the C─F bond, explaining why this so far elusive reaction is now possible at such exceptionally mild conditions.

We report the synthesis of hexafluorophosphate (PF6-) salts directly from white phosphorus (P4) and simple fluorides MF (M = Li, Na, K, Cs, NMe4) in a single step. The utilization of p-quinones, such as 2,3-dichloro-4,5-dicyano-1,4-benzoquinone (DDQ) offers a selective fluorination pathway, which affords MPF6 salts in up to 95% yield in acetonitrile (MeCN). NMR investigations of the DDQ-mediated P4 fluorination reaction revealed the formation of PF3 and PF5·MeCN as key reaction intermediates. Donor-acceptor interactions between DDQ and fluoride are critical, effectively increasing the fluoride concentration and enabling efficient fluorination to PF6-. Tetraethylene glycol (TEG) selectively stops the reaction at the adduct K[PF5·TEG]. In contrast, noncoordinating dichloromethane (DCM) favors PF3 formation by suppressing EDA interactions through low fluoride solubility, possibly via the tris(hydroquinonyl)phosphite P(DDQH)3, underscoring the critical role of fluoride solubility. This work demonstrates that quinone-fluoride interactions can be exploited for oxidative fluorination chemistry, establishing a new conceptual framework for P4 fluorination.

The surface chemistry of MXenes is a central factor governing electrochemical performance and has become increasingly complex with the emergence of molten salt etching routes. Compared with conventional fluoride-derived systems, molten salt derived MXenes exhibit chemically diverse and highly tunable surface states arising from termination chemistry, retained metal species, interfacial evolution, and post-synthetic regulation. Such synthesis-dependent complexity creates a strongly coupled design space that motivates data-driven discovery. In this review, we summarize recent progress in molten salt derived MXenes with emphasis on tunable surface chemistry and its implications for data-driven design. Surface termination engineering, metal incorporation, heterostructure formation, and post-synthetic modification are discussed as interconnected surface-regulation pathways. We further examine how synthesis history, surface chemistry, and electronic structure can be translated into physically meaningful descriptors for machine learning and high-throughput modeling. Overall, this review establishes a chemistry-informed framework linking molten salt synthesis, tunable surface chemistry, and data-driven discovery toward electrochemical applications.

Aryl organoboron reagents play an important role in modern organic synthesis, and interest in radical-based coupling reactions from these precursors has grown rapidly. However, direct electrochemical generation of aryl radicals from aryl boronic acids, ArB(OH)2, remains understudied due to their high oxidation potentials (E ox > 2 V vs. Fc/Fc[+]) and challenges associated with electrochemical processes such as electrode passivation. Aryl potassium trifluoroborate salts (ArBF3K) can be oxidized efficiently to aryl radicals is previously reported using alternating polarity electrolysis. Building on this, it is combined alternating polarity electrosynthesis with in situ fluoride activation to generate redox-active aryl fluoroborate intermediates, ArBF(OH)2 and/or ArBF2(OH), which have significantly lower oxidation potentials than their parent boronic acids or trifluoroborates. Moreover, it is found that for highly electron deficient aryl boronic acids with oxidation potentials higher than 1.7 V versus Fc/Fc[+], a different mechanism is proposed where aryl boronic acids underwent ipso-substitution with oxidatively generated P(OEt)3 radical cation. Overall, this dual mechanistic pathway allows an efficient radical-based functionalization of a broad range of aryl boronic acids to form aryl C─P bonds.

Metal organic frameworks (MOFs) have attracted increasing attention in composite solid electrolytes (CSEs), attributed to the tunable pore structures and good thermal and electrochemical stability. However, MOFs-based CSEs still exist, with a trade-off between ionic conductivity and lithium dendrite inhibition ability. Herein, 420 nm ultrathin ZIF-67 layer on polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) membrane is precisely regulated through the interfacial growth method. The organic ligand 2-methylimidazole permeates through the straight-through pore of PVDF-HFP to react with Co[2+], which controls the reaction rate to form ultrathin and dense ZIF-67. The CSE with ultrathin and dense ZIF-67 layer not only reduces Li[+] transport resistance but also promotes lithium salts disassociation, contributing to an ionic conductivity of 2.70 mS cm-[1] at 30°C and Li[+] transference number of 0.71. Meanwhile, the ultrathin ZIF-67 induces fast Li[+] transport kinetics, uniform Li[+] flux, and homogeneous Li deposition, synergizing with high mechanical strength to inhibit lithium dendrite growth. As a result, the NCM811||Li coin battery shows improved cycling performance with a capacity retention of 70% after 446 cycles at 0.5 C and is capable of working at -20°C. This work proposes an innovative design of ultrathin MOFs-based CSEs with high ion conductivity and low interfacial conduction resistance.