Accounts of materials research最新文献

{"title":"Biointerface\u0000Photocatalysis: Customized Porous Materials\u0000Enabling Synergy between Organic and Inorganic Systems","authors":"Shifei Kang,Xiao Hu,Lingxiao Xue,Yonghui Deng","doi":"10.1021/accountsmr.6c00145","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00145","url":null,"abstract":"Conspectus Integrating biological systems with inorganic photocatalysis represents a transformative leap at the nexus of materials science and the life sciences, but it encounters a fundamental incompatibility: highly reactive photogenerated species often deactivate biological components that they are intended to assist. This Account elaborates on our attempts to handle this conflict by moving the design focus from seeking intrinsic catalytic activity to appropriate engineering of interfacial gradients. To achieve biointerface photocatalysis in practice, the electronic and structural properties of inorganic materials must be strictly matched to the specific kinetic constraints of biological targets. We demonstrate that customized porous materials serve as ideal platforms to support functional biointerfaces. This framework centers on the three key functional roles of materials in actively managing the mass, charge, and signal flows. (1) mesoporous confinement acts as a kinetic filter to modulate reactive species evolution and govern mass migration. (2) structural asymmetry generates built-in electric fields to facilitate directed charge movement to specific biological targets. (3) Tailored pore structure defects and surface chemistry regulate the transduction signals and chemical gradients. Leveraging these material-driven functions, we establish bioinorganic synergy across increasing levels of biological complexity. Molecularly, fragile enzymes are spatially isolated via precise mesoporous compartmentalization. This structural mediation efficiently decouples incompatible reaction steps, so that the kinetic gap between slow enzymatic turnover and fast radical production is bridged to facilitate autonomous biocatalytic cascades. Moving to whole-cell microbes’ regulation, our effort moves to active charge management. Asymmetric interfaces and surface defects are engineered to systematically guide photoelectron fluxes into specific microbial transport chains, so we can actively rewire cellular metabolic pathways. Finally, the biointerface could act as a dynamic signal transducer within complex tissue-level models. Physical or chemical triggers are converted to specific physiological signals by combining ultrasound-responsive platforms with functionally gated porous matrices. This methodology enables the precise regulation of tissue microenvironments, ranging from localized redox modulation to logic-gated biosensing. Collectively, these three modes demonstrate how rationally tailored interfacial properties dictate the ultimate functional output of the biohybrid system. However, translating these lab-scale demonstrations into practical technologies requires overcoming formidable challenges like pore fouling, where biofilms or protein corona block mesochannels and reduce system lifespan. Furthermore, conventional evaluation metrics, such as single-site turnover frequency, are inadequate for these highly heterogeneous interfaces. Future development must ","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149092004","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":"Electrochemically\u0000Generated Single-Atom Centers of\u0000MXenes for Energy Conversion","authors":"Diwakar Singh,Totan Mondal,Ling Meng,Francesc Viñes,Francesc Illas,Kai S. Exner","doi":"10.1021/accountsmr.6c00164","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00164","url":null,"abstract":"Conspectus Single-atom catalysts (SACs) have attracted significant attention in electrocatalysis due to their ability to maximize atomic efficiency and provide well-defined active sites. However, their practical use is often limited by stability issues, since the anchored atom serving as the active site may dissolve or restructure under applied potential conditions. The material class of MXenes, two-dimensional transition-metal carbides and nitrides, offers a fundamentally different route toward SAC-like catalytic motifs. Under anodic polarization in aqueous environments, MXene basal planes can undergo water-mediated surface reconstruction to forms an electrochemically generated MXene–single-atom-center-like (MXene–SAC-like) motif in situ. These dynamically generated centers resemble archetypal SACs in their local coordination environment but differ fundamentally in that they are not created through synthetic anchoring strategies, but emerge directly under electrochemical operating conditions. In this Account, we summarize the progress of our group in understanding electrochemically generated MXene–SAC-like motifs for energy conversion processes using electronic structure theory. Pristine MXene basal planes are catalytically inactive under anodic polarization; reconstruction under applied bias generates isolated metal centers whose stability, activity, and selectivity we have mapped across the MXene compositional space. We discuss thermodynamic frameworks based on surface Pourbaix analysis and dissolution thermodynamics that provide insight into the conditions under which single-atom centers become accessible and catalytically active. These stability maps reveal a scenario-dependent W–Mo–Ta progression: W-based motifs dissolve spontaneously, Ta-based motifs are particularly robust under pre-OER conditions, whereas Mo-based motifs retain the wider OER-specific stability window at pH = 0. In addition to oxygen-, chlorine-, and nitrogen-containing reactions under anodic polarization, we also describe the use of electrochemically generated MXene–SAC-like motifs for cathodic processes by pulsing the electrochemical potential. While activity trends in electrocatalysis are commonly interpreted using adsorption free-energy descriptors, we further introduce a dual-descriptor framework that incorporates transition-state energetics into the activity ranking of homologous catalyst series. This approach provides a more complete description of activity and selectivity trends, particularly for proton-coupled electron-transfer processes involving competing reaction channels. For ammonia oxidation specifically, Brønsted–Evans–Polanyi scaling breaks down for dehydrogenated N–N coupling intermediates, and thermodynamic descriptors alone incorrectly predict the preferred coupling pathway for most MXene–SAC-like motifs. By connecting adsorption thermodynamics with reaction kinetics, this framework offers a different perspective on catalytic selectivity at electrified","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091975","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":"DC Arc Plasma\u0000Jet CVD of Diamond Materials: A Journey\u0000from Laboratory to Industrial Applications","authors":"Liping Zheng,Chengming Li,Liangxian Chen,Junjun Wei,Jinlong Liu,Xiaoping Ouyang,Fanxiu Lu","doi":"10.1021/accountsmr.6c00163","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00163","url":null,"abstract":"Conspectus Diamond possesses a unique combination of ultrahigh hardness, exceptional thermal conductivity, broadband optical transparency, and a high critical breakdown field and is regarded as the ultimate semiconductor material. Among various chemical vapor deposition (CVD) techniques for diamond synthesis, direct current (DC) arc plasma jet CVD stands out for its ultrahigh plasma density and gas temperatures (∼10,000 K), enabling the rapid, controlled growth of high-quality (up to optical-grade), large-size diamond films. Combined with its relatively low equipment cost, this technology is well-suited to the demands of industry. Early DC arc plasma jet CVD systems are limited by intrinsic equipment constraints, confining the technique to laboratory studies. Sustained efforts by research teams at the University of Science and Technology Beijing have since overcome key technical bottlenecks. A high-power DC arc plasma torch with rotating arc-root technology and a semi-closed gas circulation system enables cost-effective growth of large-area diamond materials. Moreover, stress accumulation remains a critical challenge during diamond deposition, particularly for large-area films, often leading to cracking. To mitigate this issue, composite substrates have been developed to facilitate controlled interfacial separation after growth, yielding free-standing diamond films up to 150 mm in diameter. To further extend diamond size, a 150 kW DC arc plasma jet CVD system with a dual-level magnetic field configuration is developed, providing enhanced plasma density and uniformity. At present, leveraging this technology, we achieve an annual production capacity of up to 75 million mm3 of free-standing diamond films and have established the world’s largest production line for thermal-grade diamond wafers. Meanwhile, precise control of growth parameters further enables the synthesis of diamond across a broad range of quality grades with diameters of 30–200 mm and thicknesses of 0.3–6.5 mm, meeting diverse application requirements. This includes tool-grade diamond for precision machining, diamond heat spreaders for satellite applications, optical-grade 5-inch diamond films, diamond for field-effect transistor devices, and single-crystal diamond approaching natural type IIa quality. In this Account, we summarize the evolution of DC arc plasma jet CVD, highlighting the critical innovations in reactor design and composite substrates that have transformed this technology from a laboratory approach into an industry platform for diamond manufacturing. Furthermore, through precise regulation of the growth process, diamond materials with tailored structures and properties can be engineered to meet diverse functional requirements. We believe that the continued maturation of this technology will overcome existing cost challenges, ultimately establishing diamond as a high-performance and cost-competitive advanced material for next-generation applications.","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149049998","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":"Closing the Gap:\u0000Multiresonant TADF Emitters and TADF\u0000Dendrimers in Solution-Processed OLEDs","authors":"Mahni Fatahi,Eli Zysman-Colman","doi":"10.1021/accountsmr.6c00190","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00190","url":null,"abstract":"Conspectus Organic light-emitting diodes (OLEDs) have become a cornerstone technology in modern displays, yet their dominant manufacturing route, vacuum deposition (VD), remains cost-intensive and intrinsically wasteful. Solution processing (SP) offers an attractive alternative because it enables high-throughput fabrication, reduced material loss, and compatibility with large-area and flexible substrates. Organic thermally activated delayed fluorescence (TADF) emitters are uniquely positioned for SP-OLEDs, as they can harvest both singlet and triplet excitons, providing a route to near-unity device internal quantum efficiency, without the need for scarce heavy metals. The key challenge, however, is that the performance of SP TADF OLEDs still lags behind VD devices in both maximum external quantum efficiency and efficiency roll-off. These performance gaps originate from SP-specific constraints such as unoptimized film morphology, aggregation-caused quenching (ACQ), limited control over transition dipole orientation, and charge imbalance in multilayer stacks. Consequently, closing the VD–SP performance divide requires coordinated progress in molecular engineering and device engineering. This Account summarizes recent materials-design strategies for high-performance SP TADF OLEDs, with emphasis on multiresonant TADF (MR-TADF) emitters and TADF dendrimers. Small-molecule donor–acceptor (D-A) TADF emitters, though compatible for SP-OLEDs, often show broad emission resulting from their emissive long-range charge-transfer (LRCT) states and large reorganization energies, compromising color purity. MR-TADF emitters address this limitation, providing narrowband emission from a short-range charge-transfer (SRCT) state resulting from the alternating HOMO/LUMO density on adjacent atoms. Yet even state-of-the-art MR-TADF materials that deliver outstanding VD-OLED performance yield SP-OLEDs showing a marked drop in performance, evidencing that processing-induced disorder and bimolecular quenching become dominant in these devices. We therefore highlight how contemporary MR-TADF emitter design has shifted beyond solubility improvements toward deliberate control of film-state organization (e.g., liquid-crystalline self-assembly to induce preferential horizontal dipole orientation and improve outcoupling) and excited-state kinetics (e.g., multichromophore coupling and intramolecular FRET concepts to accelerate effective triplet harvesting and reduce roll-off while retaining narrow emission). In parallel, TADF dendrimers combine the high solubility and film-forming ability of polymers with the high purities possible with small molecules. This leads to SP devices showing comparable performance to VD ones. We discuss how dendrimer design has progressed from early low-performing prototype devices to SP-OLEDs showing EQEmax approaching 30%. We discuss how dendrimer design provides additional levers to modulate charge balance and efficiency roll-off. Importantly, dendrim","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149050001","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":"Construction of Bulk Inorganic Ionic Materials by Nonclassical Reactive Precursors","authors":"Chen Luo, Yinan Fu, Yueqi Zhao, Zhaoming Liu","doi":"10.1021/accountsmr.5c00376","DOIUrl":"10.1021/accountsmr.5c00376","url":null,"abstract":"<p>Inorganicionic compounds, exemplifiedby minerals and ceramics,are essential materials for construction, optics, structural engineering,and biomedicine. The processing of these materials into bulk formsrelies predominantly on conventional sintering; however, this processtypically requires extreme temperatures and pressures. Furthermore,the limited ion diffusivity in crystalline particle precursors oftenleads to internal structural discontinuities, including pores andother defects. These imperfections compromise critical performancemetrics, most notably mechanical strength and optical transparency,posing a significant challenge for the development of high-performancemonolithic inorganic ionic materials.</p><p>Recent advances in nonclassicalcrystallization indicate that inorganicmaterials can be generated through alternative pathways involvingnonclassical inorganic precursors beyond monatomic ions. Upon controlledcrystallization, these precursors can endow inorganic materials withoptimized mechanical, optical, and bioactive properties. Our recentstudies further demonstrate that nonclassical crystallization providesfeasible pathways for manufacturing monolithic inorganic ionic materials.For example, inorganic ionic oligomers can be polymerized into moldablemonolithic inorganic ionic materials. Amorphous solid particles canfuse in a liquid-like manner under pressure, forming hard and transparentbulk inorganic ionic materials. These achievements indicate that therational selection of inorganic precursors with controllable crystallizationpathways can expand the methodological toolbox for the constructionof bulk inorganic ionic materials.</p><p>In this Account, we categorizeinorganic precursors into threetypical classes based on their structural characteristics and reactivity–stabilityprofiles, namely inorganic ionic clusters, amorphous solids, and crystallineparticles. Inorganic ionic clusters, exemplified by inorganic ionicoligomers, represent highly reactive molecule-like species. Theseprecursors enable a molecular-level processing route for inorganicmaterials, facilitating precise and continuous bottom-up fabricationof bulk inorganic solids across multiple scales. Amorphous solidsrepresent an intermediate state in which disordered structures facilitateion diffusion and structural rearrangement, thereby enabling theirfusion into bulk inorganic ionic materials. Crystalline particlesexhibit the highest thermodynamic stability but the lowest reactivityamong the precursors; their conversion into continuous bulk materialstypically requires surface activation or enhanced mass transport topromote effective fusion and ordered assembly. We summarize the uniqueadvantages of these precursors for manufacturing monolithic inorganicionic materials and propose future directions for their further development,focusing on the chemical regulation of reactivity and the establishmentof controllable pathways for bulk fabrication. Alongside these scientificadvancements, ","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 9","pages":"899–912"},"PeriodicalIF":14.1,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148805779","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":"Spontaneous Reactive Oxygen Species-Releasing Materials","authors":"Guangshun Yi, Jackie Y. Ying","doi":"10.1021/accountsmr.6c00156","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00156","url":null,"abstract":"","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 9","pages":"894–898"},"PeriodicalIF":14.1,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027895","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 Evolution\u0000in Transition-Size Gold Nanoclusters:\u0000Insights into Nucleation and Growth through the Insertion–Collapse\u0000Mechanism","authors":"Qinzhen Li,Xi Kang,Manzhou Zhu","doi":"10.1021/accountsmr.6c00224","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00224","url":null,"abstract":"Conspectus As an important research object for studying the formation and evolution of metal condensed matter, metal nanoclusters (NCs) can provide accurate structures for relevant studies, and provide visual images for exploring the metal–metal interaction and packing mode in evolution. The close structural correlation between different NCs and the realizable interstructural transformation process provide a research platform for further understanding of the conversion mechanism of their structural evolution. As NCs are connected at the evolutionary scale metal–organic complex and plasmonic metal nanoparticles, the origin of metal condensed matter can be explored from the initial stage of the formation of NCs, also known as transition-sized NCs. By exploring the structural transformation reaction of transition-size NCs, key information can be obtained regarding nucleation, changes in metal packing modes, and the size-dependent evolution of core–shell geometries and electronic structures. To clarify the geometric and electronic evolution of NCs at the early stage of formation, we synthesized a series of transition-sized Au NCs and determined their precise structures, establishing a structural evolution map for NCs containing fewer than 25 metal atoms. Using a two-phase ligand-exchange method and a phosphine-ligand-induced size-tailoring strategy, we obtained a family of transition-sized Au NCs, including Au13, Au14, Au16, Au18, Au21, Au22, and Au24. Their precise core–shell structures served as model systems for investigating structural evolution. Based on the behavioral characteristics of structural transformation between these Au NCs, we propose the insertion–collapse mechanism for understanding the size growth of transition-size Au NCs. It indicates that the growth of the transition-size NCs is characterized by the insertion of external Au-SR units and the inward collapse of the Au atoms into the kernel. Besides, based on the structural analysis between Au12(SR)12 complex and Au13 NC, the origin mechanism of the kernel in Au NCs was unraveled to be the transition from Au4(SR)4 ring to bi-trigonal Au5 kernel. Taking the Au5 kernel as a starting point, the pattern of kernel size growth in subsequent Au NCs is also clearly summarized as a sequence of Au5→Au6→Au7→Au9→Au10, which is manifested as the gradual increase in the number of Au3 and Au4 building units and kernel configuration converts from planar to three-dimensional types. Using the exact NC structures as theoretical models, we also clarified the evolution of electronic structures in transition-sized Au NCs. The calculations show a regular size-dependent trend characterized by a two-electron growth pattern in valence electron count, a decreasing HOMO–LUMO gap, and a transition in HOMO–LUMO excitation behavior from interband (sp←d) to intraband (sp←sp) transitions. While previous studies have focused mainly on static structures and structure–activity relationships, this work addresses a mor","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149050000","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":"Approach toward Optochemistry from Organic Materials Science View","authors":"Yohei Yamamoto,&nbsp;Hiroaki Yoshioka,&nbsp;Soh Kushida,&nbsp;Kenichi Yamashita,&nbsp;Daichi Okada","doi":"10.1021/accountsmr.6c00106","DOIUrl":"10.1021/accountsmr.6c00106","url":null,"abstract":"<p>This Account outlines the emergingconcept of optochemistry, anovel research field integrating optics and chemistry. While photochemistrytreats light as energy particles (photons), optochemistry defineschemistry where light is treated as propagating or standing waves.It encompasses optics that leverage the unique characteristics oforganic and polymer materials such as chirality, spin, and semiconductingproperties, as well as chemistry that exploits optical phenomena.In this sense, optochemistry can be positioned as the next evolutionarystep beyond photochemistry, utilizing the wave and phase propertiesof light.</p><p>In this Account, we first provide an introductoryoverview of thehistorical backgrounds of optics, photonics, and photochemistry, followedby detailed discussions on specific topics within optochemistry. Insection 2, we begin by describing the fabrication of microcavitiesfrom π-conjugated organic molecules and polymers and their laseroscillations, extending to applications such as optical memory, opticallogic, long-distance energy transfer, and high-sensitivity opticalsensing, as well as organic ionic liquid droplet and microcrystallasers.</p><p>In section 3, we discuss on organic microring resonatorsthat worksas structured light generators such as Bessel-Gaussian beam and opticalvortices. The control of optical vortex using organic ring resonatorsare discussed, alongside their integration into photonic (optical)integrated circuits. Next, we discuss light-matter strong couplingwithin optical cavities in section 4. In the strong coupling regime,the molecular excited states and cavity modes couple intensely, resultingin the formation of polariton states─hybridized states of lightand matter. We delve into organic polaritonics, reviewing polaritonstates and the hidden polaritonic Bardeen–Cooper–Schriefferstates in organic and metal-halide perovskite crystals, as well aspolariton lasers and the Rashba-Dresselhaus effect arising from spin–orbitinteraction of light.</p><p>In section 5, discussion shifts to uniquenonlinear optical phenomenareflecting chirality in organic–inorganic perovskite thin filmsand chiral light-matter strong coupling. Finally, we offer a perspectiveon the future transition and expansion from photochemistry to optochemistry.We envision that this conceptual framework will catalyze the birthof new chemistry that exploits the wave, phase, and beam nature oflight, as well as innovative optics driven by novel chemical phenomena.</p>","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 9","pages":"941–951"},"PeriodicalIF":14.1,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148650671","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":"Exciton Adventures","authors":"Timothy M. Swager","doi":"10.1021/accountsmr.6c00131","DOIUrl":"10.1021/accountsmr.6c00131","url":null,"abstract":"&lt;p&gt;Excitonsare mobile excitedstates in materials with propertiesand dynamics that underpin many applications of conjugated organicpolymers. Understanding these quasiparticles in organic materialsrequires knowledge of classical molecular photophysics and solid-statephysics-based descriptions of semiconducting polymers. The molecularinterpretation of an exciton is an excited state with physical sizedetermined by the region over which bond lengths/angles are relaxedfrom their equilibrium ground state geometries. The physics representationis that excitons are quasiparticles comprising a bound electron–holepair. Specifically, in the excited state the hole is a vacancy inthe HOMO (valence band) and the electron is an unpaired electron inthe LUMO (conduction band). Excitons move through multiple mechanisms.These include Förster energy transfer wherein the dipole froma virtual electronic emission is captured by a coupled chromophoreto create a new excited state. The Förster mechanism is facilitatedby the natural tendency of the high aspect ratio of conjugated polymerchromophores to align, the relatively low dielectric constant of thematerials, and the high spectral overlap of the absorptions and emissions.In a second mechanism, the exciton moves through band transport, whereinthermal phonons (traveling compression/expansion nuclear motion excitations)nudge the excitons and cause movement. This mechanism requires directorbital interactions (strong electronic coupling) and is related toDexter energy transfer in the molecular systems, wherein collisionalinteractions between molecules allow for energy transfer. Both molecularand solid-state physics perspectives are valuable in understandingexciton dynamics/mobility. Exciton transport is central to photovoltaicsand photodetectors excitons wherein these electron–hole pairsdiffuse to interfaces and separate to create electrical potentialsand/or photocurrents. Ultrasensitive chemical sensors and biosensorsbased on conjugated organic polymers exhibit amplified sensor responsesenabled by exciton diffusion. This natural amplification has beenwidely exploited for trace chemical and biological sensing, and explosivesensors have been commercial now for more than 20 years based on thisprinciple. Moreover, the polychromophore character of conjugated organicpolymers creates very large absorption cross sections and when combinedwith high emission quantum yields makes them exceptionally brightfluorescent labels, which has found use in biology. Exciton diffusionenhances photoredox catalysis wherein fast exciton diffusion increasesthe probably of encounter of the reactive excited state within a nanosecondtimeline. My studies of excitons have been guided by classical physicalorganic chemistry wherein hypotheses are tested through materialsdesign and synthesis. I will detail how receptor integration, controlof interpolymer organization, precision assembly of aligned polymers,and modulation of excited state lifetimes have pro","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 9","pages":"989–1000"},"PeriodicalIF":14.1,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148717997","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":"Design of Iron-Based Fischer–Tropsch Synthesis\u0000Catalysts for Directly Converting Syngas to Value-Added Chemicals\u0000and Clean Fuels","authors":"Yuan Li,Linkai Wang,Zhenzhan Zhang,Yanfei Xu,Mingyue Ding","doi":"10.1021/accountsmr.6c00228","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00228","url":null,"abstract":"Conspectus Fischer–Tropsch synthesis (FTS) represents a key technology for converting syngas into fuels and value-added chemicals. Despite decades of industrial application, it remains constrained by three persistent challenges: the dynamic reconstruction of active phases under working conditions, broad hydrocarbon distributions arising from complex reaction pathways, and substantial CO2 formation via the water–gas shift (WGS) side reaction. To address these challenges, our group has made continuous efforts through three stages in the last dozen years: establishing the relationship between active-phase dynamics and catalytic performance, regulating product distribution through electronic modulation and dual-site coupling, and suppressing WGS activity by engineering hydrophobic microenvironments. Relating active-phase dynamics to catalytic performance requires resolving the formation and transformation of Fe phases during FTS. Iron oxide precursors undergo reduction and carburization to form iron carbides, which serve as key active phases for CO activation, C–C coupling, and hydrocarbon formation. Analysis of the reduction and carburization pathways of Fe species, together with the evolution of surface carbon species, allowed us to correlate bulk and surface Fe-phase compositions with catalytic performance. These results provide a mechanistic basis for controlling iron carbide formation under working conditions. Building upon this understanding of active-phase dynamics, we explored strategies to direct reaction pathways and product distributions. Electronic modulation of Fe-based catalysts modified the electronic environment of iron carbide phases and, consequently, product selectivity. Spatially organized multifunctional active sites, in turn, enabled the sequential transformation of reaction intermediates through tandem catalysis. The resulting design framework links active-phase regulation with coordinated control of catalytic functions, reaction pathways, and product distribution. A key insight emerging from our studies is that reaction-generated H2O is not merely a reaction by-product but an important catalytic variable influencing active-phase stability and reaction pathways. Under FTS conditions, H2O can interact with iron carbide phases and induce oxidation to Fe3O4, resulting in enhanced WGS activity and CO2 formation. This understanding motivated the development of hydrophobic microenvironment engineering to regulate the local behavior of H2O, including its adsorption, migration, and residence time near active phases. By constructing hydrophobic interfaces and tailored porous architectures, we effectively regulated the local interaction between H2O and iron carbide phases, thereby suppressing iron carbide oxidation and the WGS side reaction while maintaining efficient transport of reactants and products. These studies trace a progression from understanding active-phase dynamics to controlling reaction pathways and, ultimately, regulating","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149050002","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}