Accounts of materials research最新文献

{"title":"Swelling–Shrinking Strategy of Polymer Nanospheres for the Creation of Novel Nanostructured Materials","authors":"Wenchao Li,Xiaoyu Li,Xin Du","doi":"10.1021/accountsmr.6c00196","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00196","url":null,"abstract":"The rational construction of polymer nanostructures with tunable architectures and integrated functions has become a central pursuit in contemporary materials science. Owing to their soft nature and environmental responsiveness, polymer nanoparticles can undergo dynamic morphological evolution under external regulation, offering an attractive platform for constructing hollow, porous, anisotropic, and hierarchically organized nanostructures. Importantly, these architectures are not merely geometric variations; they determine mass-transport pathways, regulate interfacial reactions, accommodate guest species, and govern the performance of polymer-based functional materials in catalysis, biomedicine, and related fields. Nevertheless, transforming simple polymer nanospheres into complex nanoscale architectures with high precision remains challenging. Conventional templating or etching methods often involve multistep procedures, harsh conditions, or sacrificial components, which restrict structural precision, compositional diversity, and scalability. Against this backdrop, the swelling–shrinking strategy has emerged as a controllable and versatile approach for reshaping polymer nanospheres from within. Typically, polymer particles are first induced to swell by selected solvents, temperature variation, or other external factors, allowing their internal networks to loosen, reorganize, or accommodate foreign components. Subsequent shrinking, driven by solvent exchange, chain relaxation, cross-linking, precipitation, or interfacial contraction, locks these transient states into stable nanostructures. In essence, swelling acts as a nanoscale “breathing” process that opens the polymer matrix, whereas shrinking functions as a “locking” step that sculpts and stabilizes cavities, pores, shells, and asymmetric domains. Such a controllable volume transition transforms soft polymers into sophisticated nanostructured architectures without relying entirely on rigid templates.\u0000In this Account, we present our perspective on swelling–shrinking of polymer nanospheres as a structural transformation strategy with particular emphasis on how this concept has guided our recent work on polydopamine (PDA)-based nanostructures. We use Polystyrene (PS), Poly(methyl methacrylate) (PMMA), and Resorcinol–formaldehyde resin (RF) particles as mechanistic references to clarify how solvent affinity, chain mobility, cross-linking density, and interfacial confinement regulate polymer volume change and structural fixation. These model systems help define the basic design logic: swelling creates a transient soft state, whereas shrinking locks nonequilibrium morphologies into hollow, yolk@shell, porous, or anisotropic architectures. Building on this understanding, we focus on PDA as the central material system. In our studies, PDA swelling–shrinking is coupled with interfacial adhesion, mesoporous silica assembly, photothermal response, and surface chemistry, enabling asymmetric yolk@shell ","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149226093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated Heterostructure Platform for SERS Fingerprinting of Biomolecules and Mechanistic Deciphering of Photocatalytic Intermediates","authors":"Olorunsola Praise Kolawole,Shivangee Rai,Avijit Pramanik,Sanchita Kundu,Paresh Chandra Ray","doi":"10.1021/accountsmr.6c00139","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00139","url":null,"abstract":"Surface-enhanced Raman spectroscopy (SERS), which integrates conventional Raman spectroscopy with nanostructured substrates, has emerged as a powerful, nondestructive analytical technique for label-free chemical and biological fingerprinting. Its high sensitivity and noninvasive nature have enabled real-time detection and characterization of DNA, RNA, pathogens, and disease biomarkers. Beyond biomolecular analysis, SERS has demonstrated exceptional capability for identifying, monitoring, and understanding short-lived reaction intermediates, providing critical insights into photocatalytic reaction mechanisms. Consequently, SERS continues to drive advances across chemistry, materials science, biology, and environmental monitoring, with substrate performance being fundamentally determined by the properties of the constituent nanomaterials. Zero-dimensional (0D) plasmonic nanoparticles, one-dimensional (1D) nanowires, nanotubes, and nanorods, as well as two-dimensional (2D) nanosheets, play pivotal roles in Raman signal enhancement through both electromagnetic mechanism (EM) and chemical mechanism (CM) contributions. Despite these advancements, achieving precise nanoscale control over plasmonic nanostructure organization remains a major challenge for reliable molecular fingerprinting. To address this issue, we engineered heterostructure SERS substrates with optimized EM and CM enhancement mechanisms, an emerging strategy at the forefront of SERS substrate design. Leveraging the inherent molecular specificity of Raman spectroscopy, these heterostructures successfully generate characteristic spectral fingerprints of biomolecules, thereby enhancing the sensitivity, selectivity, and reliability of biomolecular detection.\u0000In this Account, we present our research efforts toward the design and development of heterostructure-based SERS platforms for label-free molecular recognition, leveraging molecule-specific vibrational fingerprints for sensitive and selective detection. We first introduce our framework for SERS substrate engineering, which integrates precise plasmonic hot spot design to maximize EM enhancement with strategically selected semiconductors, 1D, and 2D materials that promote CM enhancement through efficient interfacial charge transfer. This synergistic design strategy has enabled the development of next-generation SERS substrates that combine ultrahigh sensitivity, excellent signal reproducibility, and application-specific functionality. Drawing on over a decade of research from our laboratory, we next present representative examples of heterostructure-based SERS platforms for biomolecular fingerprinting of viruses, bacteria, and disease-associated biomarkers. We further highlight the broader utility of these SERS platforms in photocatalytic studies, where operando SERS enables real-time monitoring of reactant consumption and product formation while simultaneously capturing the vibrational fingerprints of trace and transient interfacial react","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aramid Colloidal\u0000Aerogels: Architecting Nanofibers\u0000via Dynamic Sol–Gel Transition for Multifunctional Applications","authors":"Lishan Li,Xuetong Zhang","doi":"10.1021/accountsmr.6c00239","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00239","url":null,"abstract":"Conspectus Aerogels have long captivated materials scientists with their extreme properties─ultralow density, high porosity, and enormous specific surface area. Yet for nearly a century, their fabrication has remained trapped in a static paradigm: the sol–gel transition of small-molecule precursors requires prolonged standing times, which is fundamentally incompatible with the rapid, continuous processing of modern manufacturing. The root cause is intrinsic─precursors and gelation-inducing agents possess comparable molecular dimensions and thus similar diffusion coefficients. In dynamic environments, precursors diffuse away before the gel network can form, leading to structural inhomogeneity and poor shape fidelity. Our breakthrough came from a simple insight: by deliberately enlarging the precursor size to suppress its diffusion, one creates a diffusivity disparity with rapidly diffusing gelation agents. This simple kinetic consideration led us to propose the dynamic sol–gel transition─a colloidal approach that transforms aerogel manufacturing from a static, batch-wise process into a continuous, versatile platform capable of meeting the demands of modern industrial production. Aramid nanofibers (ANFs) emerged as ideal building blocks, inheriting the mechanical strength, thermal stability, and flame retardancy of bulk aramid while offering excellent colloidal processability and rapid proton-triggered gelation. This Account chronicles our systematic development of aramid colloidal aerogels across all dimensional architectures─from one-dimensional fibers to two-dimensional films and three-dimensional stereoscopic materials. We first solved the building-block bottleneck through microfluidic deprotonation, reducing ANF production from days to minutes while enabling continuous, scalable manufacturing with precise control over nanofiber dimensions. We then extended the dynamic sol–gel transition to fibers via wet, liquid crystal, centrifugal, and gas-blows-liquid spinning─achieving spinning speeds up to 300–700 m/s─and to films through blade coating, roll-to-roll, and electrochemical methods, each yielding distinct internal architectures ranging from isotropic to vertically aligned to horizontally layered. For three-dimensional architectures, we developed microgel-directed suspended printing for programmable spatial structuring and a twice-coagulated strategy, inspired by traditional Chinese folk arts, for configuration-editable aerogels with tensile elongation exceeding 7000%. These materials demonstrate broad application potential: thermal insulation from −196 to 300 °C, infrared stealth, electromagnetic shielding (54.4 dB), on-demand emulsification/demulsification with 99.97% efficiency, VOC adsorption (438.0 mg/g), rapid hemostasis, high-security information storage, shape-memory actuation, and wearable oxygen-generating microreactors validated at 4998 m altitude. Together, these demonstrations illustrate how the same underlying material platform c","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Where Chirality\u0000Matters in Perovskite-Based Circularly\u0000Polarized Light Emission","authors":"Chan Uk Lee,Chanju Son,Sunihl Ma,Jooho Moon","doi":"10.1021/accountsmr.6c00246","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00246","url":null,"abstract":"Conspectus Circularly polarized photoluminescence (CPL) adds an optical degree of freedom for emerging applications in sensing, information processing, counterfeiting security, and quantum communications. Developing emitters that directly generate CPL without external polarizing optics or magnetic fields is therefore of considerable interest. Halide perovskites are particularly attractive in this context owing to their high radiative efficiency, strong spin–orbit coupling, and structural flexibility. Incorporating enantiopure organic cations into low-dimensional hybrid perovskites can transfer molecular chirality to the extended metal–halide crystal lattice through asymmetric hydrogen bonding and lattice distortion, producing helicity-dependent absorption and emission near the excitonic band edge. Early studies therefore focused on enhancing circular dichroism (CD) and CPL emission by tuning organic-cation packing, octahedral tilting, and local distortions. In this Account, we examine a key question: where does chirality matter along the excitation-to-emission pathway? We first describe low-dimensional chiral perovskites as structurally well-defined model platforms for establishing structure–property relationships. We then discuss how chirality contributes to CPL emission from two closely related perspectives. At the transition level, emission dissymmetry is described by rotational strength arising from interference between the electric and magnetic transition dipole moments. Structural chirality can alter orbital mixing, parity character, and local coordination, thereby modifying the transition-dipole characteristics of excitonic states. At the electronic-structure level, strong spin–orbit coupling can facilitate transition pathway governed by spin-dependent optical selection rules, through which nonequilibrium spin populations can yield unequal emission intensities for opposite photon helicities. More recently, the chirality-induced spin selectivity (CISS) effect has provided a promising pathway in which spin-polarized carriers are generated in a chiral component and injected into a spatially distinct achiral emitter. Spin-light-emitting diodes (LEDs) and chiral-shell/achiral-core nanocrystals have consequently demonstrated that chirality need not be intrinsic to the emissive lattice when spin information is preserved until radiative recombination. Thus, inherent structural chirality alone is not a sufficient descriptor of CPL emission. These findings expand the design space from intrinsically chiral emitters to functionally separated architectures in which spin selection and light emission can be independently engineered. We highlight several directions required to translate these mechanistic concepts into predictive design rules. Quantitative evaluation of the electric and magnetic transition dipole moments is needed to establish how crystallographic symmetry determines rotational strength. Chiral perovskite nanocrystals provide additional de","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"286 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Design\u0000Strategies of Lead-Free Ternary\u0000Metal Halide Scintillators for Advanced X-ray Imaging","authors":"Yongkang Zhu,Xinyu Gao,Kenneth Yin Zhang,Shujuan Liu,Qiang Zhao","doi":"10.1021/accountsmr.6c00258","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00258","url":null,"abstract":"Conspectus The ever-increasing demand for advanced X-ray detection technologies calls for a revolution in conventional inorganic scintillators. In recent years, ternary metal halides (TMHs) have attracted extensive attention from both the scientific and industry communities owing to their strong X-ray absorption, high luminescence efficiencies, and structurally tunable characteristics, positioning them as promising candidates for next-generation scintillation materials. Generally, the performance of TMHs is governed by the synergistic interplay between metal halide structural units and organic components (ions or coordinated ligands), wherein the diverse assembly of organic and inorganic moieties affords a unique platform for rational materials design. To date, owing to the strong X-ray absorption arising from the high atomic number of Pb, lead-based TMH (Pb-TMH) scintillators represent the most explored materials for X-ray detection and imaging. However, Pb-TMHs suffer from severe self-absorption, inherent lead toxicity, and poor environmental stability, which critically impede their practical deployment. Encouragingly, lead-free TMH scintillators, particularly those based on Cu(I), Mn(II), and Sb(III), have demonstrated scintillation performances comparable to or even surpassing those of lead-based scintillators. Given this great progress, the key to advancing TMH scintillators toward practical applications lies in developing strategies for designing structural units that achieve optimal balance among scintillation performance, long-term stability, and processing compatibility. In this Account, we present a material design paradigm that employs TMH structural units as modular building blocks to construct high-performance scintillators for advanced X-ray imaging. It begins by introducing the structural types and underlying luminescence mechanisms of Mn(II)-, Cu(I)-, and Sb(III)-based TMHs, followed by a systematic discussion of the structural design strategies developed for these three systems with particular emphasis on organic ligand functionalization and inorganic polyhedral configuration modulation. Following this route, we emphasize the approaches for enhancing scintillation performance through cation engineering, core geometry modulation, coordination framework rigidity modulation, and guest molecule incorporation based on the structure–property relationships established across these three material systems. We further demonstrate that these well-designed TMH scintillators meet the diverse demands of X-ray imaging in various scenarios, including flexible curved-surface imaging, underwater imaging, dynamic imaging, and computed tomography. In addition, we highlight our unique insights into the development of advanced X-ray detection and imaging technologies, including the construction of an omnidirectional X-ray detection device and the establishment of a novel X-ray imaging mode with long-term archival storage and rewritable readout capabil","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"119 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coating-Free\u0000Low-Voltage Scanning Electron Microscopy\u0000for Native-Surface Imaging across Scale, Depth, and Time","authors":"Koji Harano,Satoshi Okada,Eiichi Nakamura","doi":"10.1021/accountsmr.6c00223","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00223","url":null,"abstract":"Conspectus Organic and hybrid materials derive their functions not only from molecular structure but also from how molecules organize across a hierarchy of length scales─their meso-hierarchies. Understanding such materials therefore requires one to observe them in their native states before imaging alters their structures. Scanning electron microscopy (SEM) is one of the most direct pathways to visualize these hierarchies; however, imaging organic materials has long been hindered by an intrinsic dilemma: high-resolution imaging relies on electrons, which inevitably causes charging on insulating specimens. While conductive metal coatings represent routine solutions, they inevitably alter the specimens by adding mass, obscuring nanostructural details, complicating elemental analysis, and preventing repeated observations of treated specimens. We encountered an analogous problem in transmission electron microscopy (TEM), where electron irradiation causes ionization that can alter the composition of insulating organic molecules. Our solution was to encapsulate individual molecules within carbon nanotubes or mount them onto their conductive walls to dissipate charge and suppress ionization, forming the foundation of a field we have termed “cinematic chemistry”. Fifteen years ago, we investigated whether an analogous strategy could be applied to observe the native surface instead of its metal-coated replica using SEM. The results revealed that observing the native surface was far more complex than merely removing the coating; it required simultaneously optimizing electron optics, landing voltage, and specimen preparation, alongside utilizing a substrate made of a conductive material, such as indium tin oxide (ITO), to preserve the native morphology of dispersed organic assemblies. To demonstrate this optimization, we spin-coated self-assembled [60]fullerene vesicles and target proteins onto precleaned ITO substrates. The uncoated specimens were then imaged at landing voltages ranging from several hundred volts to a few kilovolts. Consequently, individual avidin molecules and single gold nanoparticles on the vesicles were directly resolved on the native surface, entirely avoiding the granularity introduced by metal coatings. Over the years that followed, we realized that coating-free SEM should not be the ultimate goal. Rather, preserving the native surface allows a single instrument to continuously observe the same specimen across three dimensions: scale, depth, and time. We traced the chitin scale of a deepsea snail from its millimeter-sized fracture surface down to its constituent nanofibers; we observed the buried layers of a polymer composite and a solar cell cathode simply by raising the landing voltage. We followed the same specimen through a chemically converted perovskite precursor and the reversible, beam-driven folding of a free-standing fullerene nanofilm. The results collectively revealed the meso-hierarchy that links the molecular structure","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding the\u0000Complexity of Soft and Living Matter\u0000through Evolving Interfaces","authors":"Maja Vuckovac","doi":"10.1021/accountsmr.6c00251","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00251","url":null,"abstract":"","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149210483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Explicit Spin Regulation as an Emerging Design Paradigm in Heterogeneous Catalysis","authors":"Tingyu Lu,Yuan Huang,Ang Cao,Li Wei,Hao Li","doi":"10.1021/accountsmr.6c00167","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00167","url":null,"abstract":"Catalytic activity, selectivity, and durability arise from coupled electronic, structural, interfacial, transport, and spin-related processes. Conventional catalyst design has relied largely on electronic effects, strain or stress engineering, active-site construction, and local reaction environment control. Although these strategies have enabled major advances, they do not fully capture the spin degrees of freedom associated with open-shell transition-metal centers and magnetically responsive catalysts. Spin state, spin polarization, magnetic moment, spin density, and magnetic ordering can influence adsorbate binding, transition-state stabilization, charge transfer, and reaction pathways, yet their catalytic consequences are often grouped under the broad label of magnetic enhancement without a clear mechanistic assignment.\u0000In this Account, we develop explicit spin regulation as a framework for magnetism-informed catalysis. Magnetic enhancement describes an observed response to a magnetic field, a magnetic component, or a magnetic environment. Explicit spin regulation, by contrast, requires deliberate modulation of spin-related variables at or near catalytically active sites and a mechanistic connection to catalytic function. We organize this framework around two routes. Catalyst-integrated spin levers use promoters, interfaces, or interphases to tune the active-site spin/electronic structure, whereas field-induced spin levers introduce external fields or catalyst-localized magnetic perturbations during catalysis. Although implemented differently, both routes seek to control how the active-site spin governs adsorption, transition-state energetics, charge transfer, selectivity, stability, and durability.\u0000Our studies provide representative evidence for this framework. Promoter-induced spin modulation stabilizes the N–N dissociation transition state beyond conventional electrostatic promotion, establishing the spin-promotion effect as a catalyst-integrated design principle. In electrocatalysis, external fields, embedded nanomagnets, and magnetic proximity effects provide progressively localized perturbations that can be connected to spin-sensitive active sites, key intermediates, or local magnetic ordering. These examples also show why performance enhancement alone is insufficient. A convincing assignment should connect the imposed perturbation, the active-site spin/electronic response, the affected intermediate or transition state, and the resulting catalytic consequence. Magnetic measurements, electron paramagnetic resonance spectroscopy, element-specific X-ray spectroscopies, operando methods, kinetic analysis, and spin-polarized theory provide complementary elements of this evidence loop.\u0000Building on this mechanistic framework, we further translate the active-site spin into catalyst-design descriptors. The local metal-center spin moment can be correlated with oxygen-intermediate adsorption and activity trends, enabling descriptor-guided screenin","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149151935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tiny Pores, Big\u0000Stories: Perforating MXenes for Through-Sheet\u0000Transport in Energy and Environmental Applications","authors":"Anirban Sikdar,Miao Zhang,Jiayin Yuan","doi":"10.1021/accountsmr.6c00209","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00209","url":null,"abstract":"Conspectus Transport remains a central bottleneck limiting the practical performance of MXene electrodes and membranes. Although MXenes possess metallic conductivity, hydrophilicity, and rich surface chemistry, their two-dimensional (2D) layered architecture imposes barriers to ion and molecular diffusion. During assembly into electrodes and membranes, colloidal MXene nanosheets readily restack and force transport mainly through thin interlayer galleries. The as-formed slit channels lengthen diffusion pathways leading to sluggish kinetics. These limitations become increasingly important in compact, high-loading MXene structures, where long and tortuous transport pathways can further reduce active-site utilization and rate capability. This Account argues that in-plane pore engineering transforms MXenes from predominantly lamellar-type materials into through-sheet transport platforms. Introducing nanopores into the MXene basal planes creates transverse pathways that directly connect neighboring interlayer galleries, thereby shortening diffusion distances and increasing edge-site and basal-plane accessibility. Holey MXenes therefore represent more than simply porous MXenes; they are transport-engineered 2D materials in which nanoscale perforation provides an additional direction for the movement of ions and molecules while retaining the intrinsic advantages of the MXene framework. This concept is particularly relevant to densely assembled electrodes and membranes, where in-plane pathways enable rapid mass transport. We summarize our efforts toward the synthesis and structural engineering of holey MXenes, including oxidative perforation of MXene hydrogels, microwave-assisted ultrafast etching, controlled H2O2-mediated perforation, and radical-intensified selective etching (RISE) for the direct conversion of MAX phases into holey MXenes. Across these approaches, we identify a common oxidation-driven pathway involving localized oxidation, pore nucleation, and pore propagation. Importantly, controlled oxidation can introduce nanoholes while largely preserving the conductive MXene framework, whereas excessive oxidation leads to pore enlargement, conductivity loss, and structural degradation. We further demonstrate how through-sheet transport translates into improved performance in supercapacitors, batteries, ion capacitors, capacitive deionization, membrane separation, and water purification. In electrochemical systems, nanoholes facilitate ion access to otherwise less accessible regions of the nanosheets while increasing the density of exposed edge sites. In membranes, they provide transverse pathways that can shorten molecular transport distances across compact layered structures. These examples establish in-plane perforation as a versatile approach for coupling enhanced transport with MXene-specific electronic and surface-chemical functionality. At the same time, practical implementation requires precise and reproducible control over pore size, densit","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149151108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interface-Driven High Ionic Conductivities in Hydridoborate/Oxide\u0000Nanocomposite Electrolytes: A Pathway to High-Capacity All-Solid-State\u0000Batteries","authors":"Jonas D. Hehn,Renate J. Baarslag,Peter Ngene","doi":"10.1021/accountsmr.6c00180","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00180","url":null,"abstract":"Conspectus In the pursuit of renewable energy storage, batteries are expected to play a major role. All-solid-state batteries (ASSBs) employing solid electrolytes (SEs) as ion conductors have the potential to improve the energy density and overall safety of batteries compared to traditional batteries using organic liquid electrolytes. Hydridoborates, combinations of complex anions with the general formula [BxHy]z− and charge carrier cations such as Li+, Na+, K+, and Mg2+, have been perceived as promising SEs in recent times due to properties such as softness and suitable electrochemical stability against Li and Na metal. In pristine form, the ionic conductivities of hydridoborates are insufficient for battery applications at low to moderate temperatures. However, several methods have been developed to obtain highly conductive hydridoborate materials at room temperature. In this Account, interface engineering, a highly effective approach to obtain conductive and electrochemically stable hydridoborate/oxide nanocomposites, is elaborated. Remarkable ionic conductivities, up to three to four orders of magnitude higher compared to their pristine form, are observed upon confining hydridoborates in oxidic host materials. Generally, the nanocomposite materials are synthesized using either a mechanochemical treatment strategy or by melt infiltrating the hydridoborate in porous oxides. In the pioneering works, LiBH4 nanoconfined in SiO2 or Al2O3 was researched extensively, whereby highly mobile Li+ was observed at moderate temperatures (40 °C). Interfacial regions between LiBH4 and the oxides were affirmed to be crucial for the enhanced electrochemical properties. Various spectroscopic techniques, such as solid-state nuclear magnetic resonance, indicate chemically distinct interface species, where the hydroxyl groups of oxides are involved in interphase formation. A multitude of oxides were confirmed to be able to create highly conductive LiBH4-based nanocomposites. Similar to LiBH4 counterparts, NaBH4 was three orders of magnitude more conductive upon nanocomposite formation. From the boron K-edge electronic structure investigation, the formation of B–O-like bonds within the hydridoborate/oxide interphase was indicated. More conclusive evidence of the nature of the interface species came from X-ray Raman spectroscopy, where the weakening of the M–BH4 bond was observed, and the formation of trigonal boron moieties was determined to be key to the improved ionic conductivity. Importantly, interphase-driven enhanced electrochemical properties within hydridoborate/oxide SEs have been demonstrated in several ASSBs with promising capacity retention at room temperature. In most cases, the addition of oxides is beneficial for the electrochemical stability of the SEs This is especially true for the [B12H12]2– compounds, which show enhanced oxidative stability compared to [BH4]−, hence enabling utilization in ASSBs based on state-of-the-art high-voltage cathodes.","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149151109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}