Both the electrochemical and mechanical properties of solid-state electrolytes are crucial for achieving stable battery performance, while the widely studied NASICON-type electrolytes such as Na3Zr2Si2PO12 (NZSP) still suffer from poor conductivity and a tendency to Na metal penetration. To address these problems simultaneously, we propose an integrated chemistry-structure-mechanics design principle, in which aliovalent Sc/Mg co-doping (chemistry) regulates lattice framework and grain-boundary evolution (structure), thereby enhancing mechanical robustness (mechanics) without compromising ionic transport. The optimized sample (Na3.4Zr1.7Sc0.2Mg0.1Si2PO12) achieves a high room-temperature conductivity of 1.26 × 10-3 S cm-1 and a 25% increase in hardness compared with the Mg-free analogue. The solid-state cell assembled with this electrolyte (Na/Na3.4Zr1.7Sc0.2Mg0.1Si2PO12/Na3V2(PO4)3) shows excellent cycling stability in a wide temperature range of 0-80 °C, and retains 90% of its initial capacity after 440 cycles at 30 °C and 1 C. These results demonstrate that aliovalent co-doping to concurrently optimize lattice chemistry and ceramic microstructure is an effective route to high-performance NASICON electrolytes.
In this work, we propose a ligand–antisolvent synergistic regulation strategy to synthesize Cs–Pb–Br materials with dual antibacterial and encryption functions. An amphiphilic ligand derived from 5-bromovaleric acid (5-BVA) and oleamide (OAm) is employed with two green antisolvents (water and ethanol). The use of water as an antisolvent yields high-purity CsPbBr3 quantum dots (QDs) with water stability exceeding 50 days. These QDs exhibit potent antibacterial activity through electrostatic interactions with bacterial cell membranes achieving up to 99.8% inhibition at a low concentration of 120 μg/ml. In contrast, ethanol as the antisolvent leads to a mixed CsPbBr3/CsPb2Br5 phase. This mixed phase exhibits water-triggered fluorescence activation originating from CsPbBr3 recrystallization alongside a thermal quenching effect that enables reversible on–off fluorescence switching upon cooling–heating cycles. This water-induced fluorescence activation effect combined with reversible thermal quenching properties enables multi-level encryption. Ultimately this ligand-antisolvent synergistic regulation strategy not only offers theoretical guidance for the rational and tailored design of multifunctional perovskites but also establishes a foundation for their practical applications in complex optoelectronic and biological environments.
Manganese (Mn)-based materials, owing to their high theoretical capacity, low cost, environmental benignity, and multiple accessible valence states, are attractive cathode candidates for aqueous zinc-ion batteries (AZIBs). However, their practical application is often hindered by intrinsically sluggish electron transport, slow Zn2+ diffusion kinetics, and structural instability associated with Jahn–Teller distortion during cycling. Herein, we reported a heterostructured manganese selenide/manganese oxide@carbon (MnSe/MnO@C) composite derived from metal-organic frameworks (MOFs) via a simple thermolysis of Mn MOFs under an inert atmosphere, followed by selenization. The carbonization of Mn MOFs generates a carbonaceous framework favorable for charge transport, while the formation of the heterostructured MnSe/MnO@C introduces abundant heterointerfaces and electrochemically active sites. These structural features are consistent with the reduced charge-transfer resistance and enhanced reaction kinetics observed for the MnSe/MnO@C electrode. Furthermore, when used as the cathode material for AZIBs, the MnSe/MnO@C electrode revealed superior specific capacity and improved cyclability, exhibiting 225 mA h g−1 at 0.5 A g−1 after 500 charge-discharge cycles. Surprisingly, the electrode could achieve a reversible specific capacity of 191 mA h g−1 at 2 A g−1. The ex-situ characterization indicates a mixed Zn2+/H+ co-storage mechanism accompanied by reversible structural evolution without causing significant morphological damage. This study provides insights into the synthesis of MnSe/MnO@C, electrochemical activation, and remarkable AZIB performances, which leads to a better understanding of its potential applications.
Besides machine learned programs of structure prediction and AI driven ones, another direction for the search of novel carbon allotropes is proposed herein with the ‘structural engineering in carbon allotropes’ (SECA) operating model. SECA embeds the control of dimensionality, bonding topology, architecture, … and involves tools and rationales in solid-state chemistry helped with crystallography and support from quantum mechanics calculations of the ground state structures and the energy dependent physical properties. After a contextual introduction, methods and physical properties analysis tools, SECA offers an illustrative case study where, besides devising high symmetry 3D tetragonal C32 allotropes with original (not documented) topologies, a step ahead is made with the proposition of a pressure induced phase transition from the mixed trigonal-tetrahedral Csp2/Csp3 hybridization allotrope (α-C32) to insulating β-C32 made of only Csp3 tetrahedral hybridization, leading to significant densification. Such findings were based on establishing the respective energy-volume equations of states (EOS) leading to a transition pressure close to 40 GPa. Both allotropes present stable mechanical, dynamic and thermal properties with the sp3 β-C32 presenting specific heat CV = f(T) calculated curve in good agreement with diamond experimental data. Electronic band structures show a transition from a low band gap semiconductor α-C32 to insulating β-C32 like diamond. In so far that “material = matter + properties”, such rationalized research in solid state chemistry can be considered at the forefront of Materials Science, which holds much promise for the near future.
The development of high-performance narrowband near-infrared second window (NIR-II) phosphors remains a critical challenge in the fields of advanced bioimaging and optical thermometry. Herein, a series of Mn5+-doped ABaPO4 (A = Li, Na, K) phosphors are synthesized via conventional solid-state method, and the effect of A-site alkali metal cations on their crystal structure and luminescence properties is comparatively investigated. Mn K-edge X-ray absorption near-edge structure (XANES) spectroscopy unambiguously confirms that Mn ions are predominantly stabilized in the +5 oxidation state and exclusively occupy tetrahedral [PO4] sites in all three hosts. All samples exhibit characteristic narrowband NIR-II emission in the 1160-1200 nm range originating from the 1E → 3A2 spin-forbidden transition of Mn5+. The lattice distortion induced by different A-site cations significantly modulates the doping limit, crystal field strength, thermal stability and temperature sensing performance of Mn5+ ions. All three Mn5+-doped hosts exhibit good thermal stability. The fluorescence decay lifetime of LiBaPO4: Mn5+ reaches 772.436 μs NaBaPO4: Mn5+ shows unique energy level splitting and achieves a maximum relative temperature sensitivity of 2.43% K−1 based on the fluorescence intensity ratio technique. KBaPO4: Mn5+ possesses a highly symmetric crystal lattice and a higher doping limit, with a thermal quenching activation energy (ΔE) of 0.414 eV. This work not only provides three promising NIR-II phosphors for bioimaging and optical thermometry, but also offers new insights into the research of Mn5+-activated phosphate systems.
High-pressure metastable states are of paramount importance for realizing advanced functional properties, such as high-temperature superconductivity, multiferroics, and Dirac semiconductors. However, their practical applications are often bottlenecked by the high costs and poor yields associated with traditional physical synthesis. Consequently, utilizing chemical approaches to intercept and stabilize these high-pressure (HP) states at ambient pressure on a large scale is essential. In this review, we provide a comprehensive survey of chemical strategies, including geometric effects (chemical doping, solid-solution trapping, topotactic reactions, and epitaxial strain), nanoscale surface-energy effects, spatial confinement, and electrochemical fields that mimic the structural and functional output of physical pressure. Crucially, we propose a redefinition of “chemical pressure” that shifts the focus from macroscopic volumetric equivalence to “functional gene” -the specific local structural motifs (e.g., polyhedral crystal fields and orbital hybridization) that ultimately dictate the performance of materials. We analyze the calibration of this multi-scale chemical pressure and discuss the critical decoupling of electronic and volumetric effects, as exemplified by synergistic and antagonistic trends in superconductors and halide perovskites. Finally, we summarize current challenges of intercepting HP metastable states, including lack of advanced theoretical models and transition from thin-film models to bulk-form manufacture, and offer an outlook on exploring novel states of matter.
This study investigates the stereochemistry and electronic structure of two compounds, XeO3E and SeOF2E, both conforming to the general formula MX3E (M = Xe6+, Se4+) and featuring ns2 lone pairs (E). These orthorhombic crystals were selected to analyze the steric role of ME and the influence of lone pairs on Fluorine and Oxygen atoms. Detailed stereochemical analyses were performed using density functional theory (DFT) combined with two- and three-dimensional Electron Localization Function (ELF) mappings. The resulting metrics indicate that the ns2 radii of Xe (0.88 Å) and Se (0.85 Å) are comparable to first-period atoms, highlighting the crucial steric effect of these lone pairs on molecular shape and crystal packing. Fluorine lone pairs form electronic tori aligned along the M-F bonds, whereas oxygen lone pairs appear as twin maxima with versatile opening angles ranging from ∼100° to ∼160°, allowing flexible network adjustments. Site-projected density of states (DOS) confirm that both compounds are insulating, with energy gaps reflecting the separation between bonding and nonbonding valence states, the latter being responsible for lone pair development and their influence on the crystal structure.
Currently, developing nanoparticles (NPs) suspension with high transmittance and favorable luminescence performance is a significant research topic in liquid laser field. Herein, the NaGdF4:4%Nd core NPs and different shell thicknesses of NaGdF4:4%Nd@NaGdF4 core-shell NPs were prepared. Excited by 794 nm, the prepared NPs displays intense narrow-band near-infrared emission, originating from the 4F3/2→4I11/2 transition of Nd3+ ions. The coating of inert shell significantly enhances the luminescent properties of core NPs. Moreover, the prepared NPs were dispersed in C2Cl4 solvent, forming the stable and high transmittance NPs suspensions. The investigation of fluorescence lifetime and quantum yield suggest that the NPs suspensions can maintain good luminescence. This work reveals that the title NPs suspension is a potential candidate for liquid laser media.
Eu3+-activated red-emitting phosphors are of sustained interest for multifunctional applications. However, their poor stability under harsh conditions, such as high temperatures and aqueous environments, critically limits their advancement in lighting and optical security technologies. Herein, the molybdenum tellurate Ca3(TeO3)2(MoO4) (CTMO) is activated by Eu3+ for the first time, realizing bright red emission with high stability. In parallel, to reduce defect-induced non-radiative transitions due to the non-equivalent substitution of Eu3+ for Ca2+, the enhancement of co-doping alkali metal (A+ = Li+, Na+, K+) on the red luminescence is demonstrated thoroughly. The incorporation of the co-dopant Na+ delivers a 3-fold enhancement in emission intensity, along with a 1.56-fold increase in quantum efficiency. Besides, the optimized CTMO:Eu3+,Na+ powder exhibits improved luminescence stability at high temperature. When incorporated into a white-lighting device, warm white light with low correlated color temperature (CCT = 3775 K) is achieved. Meanwhile, the security ink is prepared by dispersing the resulting powder into polydimethylsiloxane (PDMS) matrix, enabling screen printing, coating, and handwriting to create security patterns on various substrates (woven/non-woven fabrics, paper, glass, and plastic sheets). The ink retains bright luminescence after immersion in water for 40 days. This investigation significantly boosts the multifunctional applicability of Eu3+-activated red-emitting phosphors for lighting and long-lasting optical security.
Superconductivity is one of the most amazing properties that metallic conductors exhibit. Electrical resistance is completely eliminated below the critical temperature (Tc), which is the most important parameter in superconductivity. Since the discovery of copper oxide superconductors 39 years ago, many solid state chemists have made significant contributions to the field by discovering new compounds and producing high-quality samples for physical measurements. However, superconductivity research remains challenging for most solid state chemists because it requires knowledge of complicated solid state physics. This manuscript aims to provide a simple, intuitive introduction to superconductivity using only fundamental physics concepts that solid state chemists are familiar with. The author investigates a wide range of materials and classifies them according to the superconductivity mechanisms that may drive them. Specifically focusing on a series of copper oxide superconductors with the highest Tc at ambient conditions, the remarkable material dependence of Tc and the underlying, unconventional superconductivity mechanism that leads to the high Tc are thoroughly examined. Although our understanding of cuprate superconductivity is still fragmented, the author believes that once the branches and leaves are removed, the story will be fairly simple, similar to the phonon-based superconductivity mechanism revealed by the BCS theory. Furthermore, potential strategies for raising the Tc of cuprates and other superconductors are discussed. The author hopes that this article will pique interest in superconductors in young solid state chemists and encourage them to pursue the discovery of still unknown and unexplored room-temperature superconductors in the future.
In the orthorhombic system, starting from inserting carbon into ultra-dense/ultrahard/metastable/metallic novel C6 with distorted C4 tetrahedra, a dense/superhard/stable/insulating C8, with regular C4 tetrahedra was found and characterized with properties close to Diamond. Such C6→ C8 transformation was then inscribed within an original protocol establishing systematics in “C4+2m” 3D stoichiometries in relation with Diamond, featuring regular tetrahedra/versus distorted tetrahedra allotropes, where m is an odd or even integer. Odd m values lead to superdense, ultrahard, metastable C6, C10, C14 whereas m even values give superhard Diamond-like stable C4, C8, C12. The obtained dia-C4, sql-C6, dia-C8, 42T1164-HZ C10, dia-C12 sequence alternates from one type to the other with increasing amounts of carbon. Such findings are proposed as a holistic vision of carbon allotropes characterized by exceptional mechanical and electronic properties.
The evolving need for eco-friendly and efficient energy storage devices has prompted the exploration of sustainable electrode materials. Biomass-derived porous carbon stands out from traditional carbon materials due to its supercapacitor application advantages, which include natural availability, cost-effectiveness, low carbon superstructure porosity, easy structural modification, and heteroatom content. This review focuses on synthesis and structural performance of biomass-derived porous carbon electrodes, while also highlighting their electrochemical functionality and practical challenges. Recent research shows significant electrochemical performance, including specific capacitance over 300F/g, energy density of 60 Wh/kg in asymmetric configurations, and sustained cycling stability (greater than 90% after 10,000 cycles). These advances have been offset by critical obstacles including feedstock inconsistency, environmental challenges from chemical activation, limited scalability, lack of measurement standards, and performance benchmarks. This review describes such gaps in detail and proposes green material synthesis, eco-friendly machine learning design, and lifecycle sustainability furthering material performance as primary focal points.
This review systematically explores the pivotal role of wettability in the crystallization of REBa2Cu3O7-x (REBCO) superconductors, highlighting its impact on crystal growth, structural quality, and superconducting performance. The discussion involves three fabrication methods: Top-Seeded Solution Growth (TSSG), Traveling-Solvent Floating-Zone (TSFZ), and Top-Seeded Melt Growth (TSMG). Conventional Y2O3 crucibles lead to severe Ba–Cu–O liquid loss, while modified crucibles, such as Fe–Y2O3 and Ca–ZrO2 reduce wettability, allowing stable growth of large, doped crystals. In TSFZ processes, modified precursor rods (Y2O3+Ba2Cu3Oy) with low wettability effectively suppress liquid migration and stabilize the molten zone, facilitating Y123 crystal growth. For TSMG approach, the thermal stability of REBCO film seeds correlates with melt wettability, with compositional modifications such as Ba-rich melts or buffer layers optimizing interfacial energy to enhance seed performance. These insights into tailored wettability provide practical guidelines for optimizing REBCO crystals and offer transferable principles for other advanced materials.
Rechargeable batteries are indispensable for diverse applications, yet their further development remains hindered by serious limitations. Rapid Joule heating (RJH), featured by ultrafast heating and cooling rates, extreme temperature, and non-equilibrium conditions, has recently emerged as a green and efficient strategy for battery material design. It enables the rapid synthesis of functional materials, including single atoms, metastable phases, nanocarbons, and metal-based compounds, while offering versatile structural engineering, such as crystallinity enhancement, defect/dopant incorporation, heterostructure construction, and interfacial optimization, effectively enhancing ion transport, reaction kinetics, and long-term stability. This review outlines the fundamental principles, structural regulations, and recent advances of RJH in rechargeable batteries, providing insights into the rational design of next-generation high-performance energy storage systems.
High-entropy polyelement nanoparticles (HEPNs) exhibit unique behaviors distinct from those of the solid phases of individual elements. The disordered nature of multielement compounds introduces structural complexity and unprecedented compositional variations, necessitating a comprehensive understanding of stabilization enthalpy, entropy, and property optimization. HEPNs are particularly desirable when fabrication methods provide precise control comparable to that achieved conventional alloy design. Recent advancements in fabrication techniques have enabled greater control over the inherently disordered structures of HEPNs. This study explores emerging strategies for synthesizing HEPNs with tunable compositions, tailored atomic configurations, and enhanced catalytic activity achieved through the formation of novel active catalytic sites. It discusses fabrication pathways for different types of HEPNs, their stabilization mechanisms, and catalytic performance, providing insights into how of various synthesis approaches influence these properties. Collectively, these strategies enable the rational design and predictable controlled modulation of catalytic activity and atomic order within the disordered lattice, establishing a basis for enhanced applications.
In this study, the nickel and iron layered double hydroxides cathode with abundant hydrogen vacancies (NiFe-LDH(v)) was designed and optimized via a two-step electrochemical deposition-activation strategy for aqueous zinc-ion batteries (AZIBs). By controlling the Fe/Ni molar ratio, the morphology, chemical bonds, electronic structure, and hydrogen vacancies distributions of NiFe-LDH(v) can be regulated. The optimized NiFe-LDH(v)-75 exhibited a high specific capacity of 173.06 mAh g-1 at 1 A g-1, and maintained 89.61% capacity after 3000 cycles at 6 A g-1, demonstrating excellent electrochemical reversibility and structural stability. Electrochemical tests, structural characterization and theoretical calculations indicate that the NiFe-LDH(v) exhibits a hybrid energy storage mechanism, including the Zn2+ chemical conversion, Zn2+ intercalation/deintercalation, and proton-coupled electrochemical transfer. During the cycling process, Ni acts as the main redox active center; while Fe regulates the electronic structure and enhances the M–O bond strength. It is noteworthy that although the contribution of Fe to the specific capacity is limited, its enhancement effect on cycling stability is very significant. Therefore, the synergistic effect of Ni and Fe is crucial for constructing the NiFe-LDH(v). This study clarifies the key regulatory role of Fe in the structure and electrochemical performance of NiFe-LDH(v), providing a reliable experimental basis for the rational design of efficient cathode for aqueous zinc-ion batteries.
The integration of graphene with diamond holds great promise for all-carbon materials, yet the precise mechanism governing graphene formation on diamond has remained unclear due to the lack of direct experimental evidence. Conventional preparation methods often rely on empirical annealing parameters. In this study, the catalytic transformation from diamond into graphene or graphite (nickel (Ni) as a catalyst) is investigated through in-situ heating transmission electron microscopy (TEM). We demonstrate that the transition proceeds via a metal-induced solid-state mechanism that is driven by Ni catalysis and reaction-diffusion between Ni and carbon (C) atoms at elevated temperatures. Key processes include Ni grain migration and C–Ni interdiffusion. The annealing duration significantly influences the location and number of graphene layers. Notably, prolonged annealing causes the development of graphene on the Ni surface, whereas rapid, short-term annealing results in the formation of graphene at the diamond/Ni interface. Extended high-temperature exposure increases the number of graphene layers, potentially facilitating graphite formation. Ab initio simulations reveal the polymerization pathway of carbon within the Ni(C) solid solution during graphene nucleation. These insights provide valuable guidance for designing application-specific graphene-on-diamond (GOD) structures, promoting the development of advanced carbon-based technologies.
The increasing demand for high-performance energy storage has intensified the pursuit of alternatives to conventional lithium-ion batteries. Lithium-sulfur (Li-S) batteries are promising due to their high theoretical energy density (2600 Wh kg-1), low cost, and sulfur’s environmental benefits. However, traditional Li-S systems face challenges including polysulfide shuttle effects, lithium dendrite formation, and limited cycle life. Incorporating solid-state electrolytes (SSEs) enhances safety and stability by replacing flammable liquids. Recent progress in solid-state Li-S (SSLS) batteries includes development of high-conductivity SSEs (sulfide, halide, polymer-ceramic composites), engineered electrodes that accommodate volume changes and minimize interfacial resistance, and improved cathode architectures for optimized ion/electron transport. Advances in stabilizing lithium metal anodes further support performance gains. Despite these improvements, challenges remain in achieving high ionic conductivity at practical temperatures, controlling long-term interfacial stability, enabling cost-effective manufacturing, and mitigating mechanical stresses from volume expansion. Future research should emphasize multifunctional materials integrating reaction and interface engineering, alongside optimized cell designs, to accelerate scalable SSLS battery commercialization.
Presently Fe3+-doped NIR phosphors exhibit immense potential for multiple applications. However, a more comprehensive understanding of Fe3+ site-occupancy and luminescent mechanism is urgently needed for enhancing material design and synthesis. In this work, a high-efficient NIR-I emitting Fe3+-doped NaAl11O17 phosphor was synthesized and systematically studied. A hybrid density functional theory (DFT) calculation was performed on geometric and electronic structures to study Fe3+ occupation preference and the corresponding optical properties. It is found that Fe3+ prefers to occupy AlO4 sites with lower total energy compared with AlO6 sites. Under 340 nm excitation, NaAl11O17: Fe3+ phosphors exhibited a high-efficient NIR emission of 600∼1000 nm peaking at ∼770 nm, with a high internal quantum efficiency of 78.12 %. Based on both theoretical and experimental results, the 3d energy-level diagram of Fe3+ in NaAl11O17 is constructed and discussed with crystal field strength analysis. The optimal NaAl11O17: Fe3+ phosphor shows good thermal stability while keeping 87 and 45 % of room-temperature intensity at 373 and 473 K. A NIR pc-LED was fabricated and demonstrates applications in nondestructive detection and angiography. This hybrid investigation on Fe3+-doped NaAl11O17 NIR-I phosphor could provide an insight for developing Fe3+-activated NIR luminescent materials with excellent performance and expanding their application prospects.
