Ali Zavabeti

A liquid metal approach synergised by a bridge solubility strategy is employed for incorporation of insoluble nonmetal fluorine into liquid tin, allowing harvesting of ultrathin F-doped SnO ₂ as a transparent conductive oxide.

Metal–phenolic network (MPN) films are of widespread interest because of their potential application in biotechnology, catalysis, and the environment. Their formation typically involves the supramolecular assembly of phenolic ligands and metal ions from solution onto a solid substrate. Such assembly has been conducted exclusively from a single-phase solution, thus limiting spatiotemporal control over coordination and/or the range of precursors that can be used, and thereby restricting the compositional and structural diversity, as well as functionality, of MPN films. Herein, we report a liquid–liquid interfacial assembly (LLIA) approach, which leverages two immiscible phases, to prepare functional MPN films with specific properties. LLIA enables both the kinetic regulation of film growth (a key parameter in designing films with desired properties) and the use of a broader range of building blocks. The assembled MPN films exhibit controlled thickness (∼30–500 nm) and stiffness (∼2–12 GPa) and distinct structural properties (e.g., crystallinity) relative to other methods, which contribute to their conductivity and molecular selectivity (e.g., H2/CO2 separation performance). Functional MPN films with wettability, conductivity, antibacterial, or fluorescence properties are assembled by integrating various functional components (e.g., polymers, nanoparticles, and dyes), as well as inorganic and metal–organic framework films.

Plants release polyphenols into soil under stress, yet their role in regulating soil mineral structure and nutrient availability is unclear. Herein, tannic acid (TA), a representative plant‐derived polyphenol, is used to first demonstrate the role of natural mineral particle restructuring in soil to control nutrient availability—a phenomenon that is facilitated through the formation of amorphous metal–phenolic complexes. From these findings, a coordination‐driven assembly strategy is devised to engineer minerals with tunable crystallinity via coprecipitation of TA and minerals (calcium phosphate and struvite). These nature‐inspired hybrid minerals exhibit reduced crystallinity (up to 46% relative to the control minerals) depending on the amount of TA incorporated (up to 17%), enabling tunable disassembly behavior. The TA‐loaded minerals exhibit enhanced nutrient release and polyphenol codelivery under biologically relevant conditions, primarily driven by TA‐induced destabilization of the mineral lattice. Pot experiments reveal increased biomass production (up to 2.5‐fold) using the TA‐loaded minerals, largely due to enhanced nutrient bioavailability, stimulatory effects of TA on crop growth, and enrichment of crop‐beneficial microbes. The findings unveil the role of plant polyphenols in regulating soil mineral dynamics and demonstrate a strategy for designing fertilizers that leverage plant–soil–microbe feedback mechanisms.

Liquid‐metal‐derived 2D materials have emerged as a versatile class of ultrathin systems enabled by dynamic and chemically active liquid metal interfaces. The atomically smooth, self‐limiting surface layers formed at these interfaces provide unique pathways for the synthesis and transfer of ultrathin post‐transition metal materials, supporting applications in optoelectronics, sensing, energy, and catalysis. However, material formation at liquid metal interfaces is governed by complex interfacial chemistry involving redox reactions, alloy thermodynamics, atomic migration, reactive atmospheres, and processing conditions. These processes directly influence crystal formation, phase, stoichiometry, and the generation of point, planar, and morphological defects. Here, we review how liquid metal interfaces control crystal and defect formation in 2D materials, highlighting key factors that influence defect formation, including atmospheric conditions, alloy composition, doping, and post‐processing. We also discuss how these defects influence their electronic, optical, sensing, and piezoelectric properties. By reframing defects as tunable design parameters rather than unavoidable limitations, this Review establishes liquid metal interfacial chemistry as a powerful framework for engineering functional 2D materials with tailored properties and improved technological performance.

Characterizing metal solubilities in post-transition-based liquid metals remains challenging due to their inherent opacity to conventional light-based analytical techniques. In this work, we present an in situ heating methodology within a transmission electron microscope that enables direct probing of the behavior of solid metal solutes within the local boundaries of liquid metal nanodroplets. Specifically, we show that the solubility of transition and precious metals in liquid state metallic solvents is dependent on the droplet size that contains them due to the internal Laplace pressure. We also show that the dissolution behaviors of solute metals in gallium–indium and gallium–indium–tin eutectic nanodroplets deviate from that of pure gallium, with solvent composition influencing solubility. Moreover, entropy-driven solubility effects are studied in multicomponent alloys that contain several solutes. The outcomes of this work are crucial for advancing liquid metal-based functionalities of soft systems, particularly for catalysis.

The structure type and phase assemblage of “layered” Na-transition metal (TM) oxides dictate their performance as cathode materials, resulting in an impetus toward developing biphasic or hybrid Na-TM-oxides. However, a fundamental understanding as to what drives the formation of such biphasic structures, instead of a single phase, remains unestablished. This also means that a coherent strategy to rationally design hybrid Na-TM-oxides and tune the relative contents of the constituent phases is missing. Against this backdrop, we report a simple strategy and an associated descriptor, that is based on the overall covalency of cation−oxygen bonds in the TMO2-“slab”, viz., the average charge-to-radius ratio of the cation combination in the TM-layer. Tuning the above parameter gives access to compositions leading to either phase-pure or biphase/hybrid O3/P2-type structures with varied relative contents of the constituent phases (at least in qualitative terms) for a fixed Na-content. The usage of this simple descriptor and the associated phase map has been successfully demonstrated here by developing a series of phase-pure and hybrid P2/O3-structured Na-TM-oxides based on two Na-contents using the same synthesis protocol. This confirms the suitability of this rational design strategy across various compositions, which can be adapted for widespread development of biphasic/hybrid “layered” TM-oxides for usage as cathode materials for Na-ion batteries and beyond.

The hydrogen evolution reaction (HER) exhibits pH‐ and electrolyte‐dependent pathways, imposing intrinsic challenges on the development of catalysts that operate efficiently across wide pH conditions and in seawater electrolysis. Here, we report a dual‐single‐atom catalyst with proximate cooperative Pt and Ni sites on a MXene (Ti ₃ C ₂ T _x ) platform that enables synergistic optimization of HER elementary steps. A one‐step molten salt‐assisted strategy, free of F‐based chemicals, allows the construction of high‐density, well‐dispersed Pt and Ni single atoms on MXene with well‐defined coordination environments. Atomic‐resolution microscopy and x‐ray absorption spectroscopy confirm the stabilization of isolated Pt and Ni sites, while in situ synchrotron‐based FTIR and DFT calculations reveal that proximate Ni sites modulate the electronic structure of Pt, weakening hydrogen adsorption and promoting water dissociation. As a result, the Pt _SAs Ni _SAs /Ti ₃ C ₂ T _x delivers low overpotentials of 22.6 and 59.1 mV at 100 mA cm ⁻² in acidic and alkaline electrolytes, respectively, and maintains high activity in neutral electrolyte (282 mV) and alkaline seawater (73.2 mV) with stability up to 100 h, outperforming commercial 20% Pt/C. These findings demonstrate that leveraging the intrinsic surface chemistry of MXenes enables cooperative dual‐single‐atom architectures with synergistically optimized HER pathways, driven by inter‐site electronic coupling across diverse pH conditions.

Atomically thin β-Ga2O3 represents an emerging class of two-dimensional oxides whose functional properties arise from a combination of ultrawide band gap electronic structure, mixed ionic–covalent bonding, and defect-sensitive local symmetry. Here, we systematically probe the tribological, electronic, and electromechanical behavior of ultrathin nonstoichometric monoclinic β-Ga2O3–δ and show that all three responses exhibit features consistent with defect-mediated interactions. Friction force microscopy reveals that nanoscale friction is reversibly modulated by external bias and displays pronounced asymmetry between positive and negative voltages, suggesting a role for field-induced charge trapping that alters interfacial electrostatic forces. Hall measurements from 100 to 400 °C show negligible current and no measurable mobility, indicating strong carrier localization and deep-level trapping that suppress free-carrier transport in the ultrathin limit. Dual-AC-resonance piezoresponse force microscopy measurements yield a reproducible out-of-plane electromechanical response (d33eff ≈ 4–5 pm/V), consistent with local symmetry breaking that may originate from surfaces, strain, or point defects. While X-ray photoelectron spectroscopy confirms the presence of oxygen-related states, we do not attribute the observed functionalities to vacancies alone; rather, the combined data indicate that the defect- and symmetry-sensitive electronic structure plays a central role across the tribological, electronic, and electromechanical domains. These findings position atomically thin β-Ga2O3–δ as a multifunctional oxide platform in which interfacial mechanics, charge localization, and emergent electromechanical coupling can be sensitively tuned for next-generation nanoscale devices.