Seungil Lee, Pedro Oliveira, Mehdi Shamekhi, Raaja Rajeshwari Manickam, Woo Young Kim, Jong Hyun Lim, Ayse Turak
Zinc-based rechargeable batteries are a promising low-cost alternative for grid-scale energy storage, but their lifetimes are limited by dendritic growth and side reactions at the metal anode. Here, we demonstrate a simple solution-based strategy to stabilize Zn anodes using a periodically sparse array of gold nanoparticles (Au NPs) deposited by reverse micelle templating. Unlike dense coatings or randomly aggregated particles, isolated Au NPs act as uniformly distributed nucleation sites that homogenize local charge fields, enhance ion transport, and suppress dendrite formation while preserving the active Zn surface. The process, achieved by gold-halide-loaded block copolymer micelles followed by plasma etching, provides precise nanoparticle size control and reproducible submonolayer coverage. Electrochemical testing shows reduced nucleation barriers, improved charge transfer kinetics, and markedly enhanced cycling stability, with symmetric cells exceeding 4000 hours of operation and delivering up to 50-fold lifetime improvements compared to bare Zn. Full-cell tests with V2O5 cathodes further confirm the improved efficiency and stability of Au NP-modified anodes. This work highlights nanoparticle decoration as a cost-effective and scalable interface engineering strategy for achieving long-life Zn batteries without compromising active surface area.
{"title":"Sparse Au nanoparticle arrays modulate Zn nucleation pathways and ion transport: a mechanistic approach to dendrite-free aqueous battery cycling","authors":"Seungil Lee, Pedro Oliveira, Mehdi Shamekhi, Raaja Rajeshwari Manickam, Woo Young Kim, Jong Hyun Lim, Ayse Turak","doi":"10.1039/d5ta08137h","DOIUrl":"https://doi.org/10.1039/d5ta08137h","url":null,"abstract":"Zinc-based rechargeable batteries are a promising low-cost alternative for grid-scale energy storage, but their lifetimes are limited by dendritic growth and side reactions at the metal anode. Here, we demonstrate a simple solution-based strategy to stabilize Zn anodes using a periodically sparse array of gold nanoparticles (Au NPs) deposited by reverse micelle templating. Unlike dense coatings or randomly aggregated particles, isolated Au NPs act as uniformly distributed nucleation sites that homogenize local charge fields, enhance ion transport, and suppress dendrite formation while preserving the active Zn surface. The process, achieved by gold-halide-loaded block copolymer micelles followed by plasma etching, provides precise nanoparticle size control and reproducible submonolayer coverage. Electrochemical testing shows reduced nucleation barriers, improved charge transfer kinetics, and markedly enhanced cycling stability, with symmetric cells exceeding 4000 hours of operation and delivering up to 50-fold lifetime improvements compared to bare Zn. Full-cell tests with V<small><sub>2</sub></small>O<small><sub>5</sub></small> cathodes further confirm the improved efficiency and stability of Au NP-modified anodes. This work highlights nanoparticle decoration as a cost-effective and scalable interface engineering strategy for achieving long-life Zn batteries without compromising active surface area.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"16 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giulliana Andrea Silva Testa, Marta Santos Rodríguez, Juan Carlos Martínez-López, Angel E. Lozano, Cristina Alvarez, Javier Carretero-Gonzalez, Evan Zhao
Polymeric membranes play a key role in redox flow batteries, where they regulate ion transport and contribute to overall battery performance. Current benchmark membranes are usually perfluorinated, which increases cost and environmental impact. Here, we synthesized and tested biphenyl-isatin polymers as cation exchange membranes in a pH neutral iron-based symmetric redox flow cell. We examined the effect of sulfonation on membrane perm selectivity by measuring the diffusion of common supporting electrolytes (LiCl, NaCl, KCl) and assessing crossover rejection of larger redox-active anions such as ferricyanide. The membrane with the highest performance was implemented in a symmetric ferro/ferricyanide- based symmetric redox flow cell, demonstrating 92% capacity retention over 180 cycles. These findings indicate that fluorine-free sulfonated polymers can serve as viable alternatives to perfluorinated membranes in electrochemical technologies. In parallel, we demonstrated an operando benchtop NMR method with atomic specificity for identifying and quantifying the Li+ charge-balancing ions through the biphenyl-isatin-based membrane. The process involved addressing paramagnetic relaxation attenuation of 7Li NMR intensity by first quantifying ferricyanide ions with the Evans method, followed by applying relaxation correction. We observed that at low current densities, Li⁺ ions served as the primary charge-balancing species, whereas at higher current, a deviation between charge and Li⁺ concentration emerged, suggesting additional contributions from other ionic species. The relaxation-correction protocol introduced here enables accurate quantification of ion transport in symmetric redox flow cells containing paramagnetic species such as ferricyanide and potentially many organic radicals. This approach provides a general framework for studying ion transport and guiding the design of next-generation membranes for diverse redox chemistries.
{"title":"Operando Benchtop NMR Study of Ion Transport through Fluorine-Free Polymer Membranes in a Symmetric Redox Flow Cell","authors":"Giulliana Andrea Silva Testa, Marta Santos Rodríguez, Juan Carlos Martínez-López, Angel E. Lozano, Cristina Alvarez, Javier Carretero-Gonzalez, Evan Zhao","doi":"10.1039/d5ta06160a","DOIUrl":"https://doi.org/10.1039/d5ta06160a","url":null,"abstract":"Polymeric membranes play a key role in redox flow batteries, where they regulate ion transport and contribute to overall battery performance. Current benchmark membranes are usually perfluorinated, which increases cost and environmental impact. Here, we synthesized and tested biphenyl-isatin polymers as cation exchange membranes in a pH neutral iron-based symmetric redox flow cell. We examined the effect of sulfonation on membrane perm selectivity by measuring the diffusion of common supporting electrolytes (LiCl, NaCl, KCl) and assessing crossover rejection of larger redox-active anions such as ferricyanide. The membrane with the highest performance was implemented in a symmetric ferro/ferricyanide- based symmetric redox flow cell, demonstrating 92% capacity retention over 180 cycles. These findings indicate that fluorine-free sulfonated polymers can serve as viable alternatives to perfluorinated membranes in electrochemical technologies. In parallel, we demonstrated an operando benchtop NMR method with atomic specificity for identifying and quantifying the Li+ charge-balancing ions through the biphenyl-isatin-based membrane. The process involved addressing paramagnetic relaxation attenuation of 7Li NMR intensity by first quantifying ferricyanide ions with the Evans method, followed by applying relaxation correction. We observed that at low current densities, Li⁺ ions served as the primary charge-balancing species, whereas at higher current, a deviation between charge and Li⁺ concentration emerged, suggesting additional contributions from other ionic species. The relaxation-correction protocol introduced here enables accurate quantification of ion transport in symmetric redox flow cells containing paramagnetic species such as ferricyanide and potentially many organic radicals. This approach provides a general framework for studying ion transport and guiding the design of next-generation membranes for diverse redox chemistries.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"90 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu Wu, Qi Qian, Cheng Xu, Zhijun Chen, Kun Zhang, Xinran Du, Jianyong Ouyang
Ionic thermoelectric (TE) materials have emerged as the next-generation TE materials mainly due to their high thermopower, which is higher than that of their electronic counterparts by 2–3 orders of magnitude. However, they cannot be used to continuously harvest heat because no electricity can be generated under a steady temperature gradient. Herein, we report a mixed ion-electron thermoelectric conductor that can be used to continuously harvest heat not only under fluctuating temperatures but also under a steady temperature gradient. It is made of an ionogel added with poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS, a conducting polymer), and it is a mixed ion-electron conductor because the ionic liquid is an ionic conductor, while PEDOT:PSS is an electronic conductor. MTEGs can continuously supply electricity to an external load even under a steady temperature gradient, which is similar to that of the conventional thermoelectric generators (TEGs) with electronic TE materials. Thermopower is related to the steady open-circuit voltage generated under a steady temperature gradient, and it is a metric calculated as the thermovoltage divided by the temperature gradient. It can reach a value of 13.87 mV K−1, which is higher than the Seebeck coefficient of the best electronic TE materials by 2–3 orders of magnitude. The TE performance is attributed to the synergistic effects of hole tunneling across the PEDOT:PSS networks and the Soret effect of the ions, which involves the accumulation of cations and anions at the two ends of an ionogel under a temperature gradient.
{"title":"Continuous heat harvesting by an ionogel mixed with PEDOT:PSS under both fluctuated and steady temperature gradients","authors":"Yu Wu, Qi Qian, Cheng Xu, Zhijun Chen, Kun Zhang, Xinran Du, Jianyong Ouyang","doi":"10.1039/d5ta09294a","DOIUrl":"https://doi.org/10.1039/d5ta09294a","url":null,"abstract":"Ionic thermoelectric (TE) materials have emerged as the next-generation TE materials mainly due to their high thermopower, which is higher than that of their electronic counterparts by 2–3 orders of magnitude. However, they cannot be used to continuously harvest heat because no electricity can be generated under a steady temperature gradient. Herein, we report a mixed ion-electron thermoelectric conductor that can be used to continuously harvest heat not only under fluctuating temperatures but also under a steady temperature gradient. It is made of an ionogel added with poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS, a conducting polymer), and it is a mixed ion-electron conductor because the ionic liquid is an ionic conductor, while PEDOT:PSS is an electronic conductor. MTEGs can continuously supply electricity to an external load even under a steady temperature gradient, which is similar to that of the conventional thermoelectric generators (TEGs) with electronic TE materials. Thermopower is related to the steady open-circuit voltage generated under a steady temperature gradient, and it is a metric calculated as the thermovoltage divided by the temperature gradient. It can reach a value of 13.87 mV K<small><sup>−1</sup></small>, which is higher than the Seebeck coefficient of the best electronic TE materials by 2–3 orders of magnitude. The TE performance is attributed to the synergistic effects of hole tunneling across the PEDOT:PSS networks and the Soret effect of the ions, which involves the accumulation of cations and anions at the two ends of an ionogel under a temperature gradient.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"61 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, organic mixed conducting polymers and small systems have shown great potential in bioelectronics, neuromorphic devices and transient electronics. Current mixed conducting materials are mostly derived from pre-existing semiconductors functionalised with polar ethylene glycol side chains; however, these materials still exhibit limited biocompatibility and degradability. Here, we develop a computational/in silico screening pipeline to investigate the potential of bioinspired building blocks as next-generation materials for organic mixed ionic-electronic conductors (OMIECs). Leveraging sustainable design principles and predictors for electronic charge transport and aggregation/conformational order, we compare two approaches to discover potential new mixed conductors: a computational funnel and a genetic algorithm. We apply and evaluate both approaches against a chemical design space created by matching conjugated fragments from the literature on organic semiconductors, hydrolysable linkers and bioinspired fragments, for a total of almost 25000 unique combinations. Our study demonstrates that, despite the limited chemical diversity of our dataset, both approaches successfully discover many potential donor-linker-acceptor (D-L-A) systems with promising features, namely: low HOMO-LUMO gap, high inter-ring planarity, and low reorganisation energy. We then down-select a few D-L-A systems and symmetrically extend their conjugation to obtain small-molecule prototypes, which show competitive reorganisation energies (as low as 123 meV). We propose that this workflow could be applied to larger datasets and tailored to discover novel chemical motifs for OMIECs and other applications.
{"title":"Computational screening of bioinspired mixed ionic-electronic conductors","authors":"Tristan Stephens-Jones, Micaela Matta","doi":"10.1039/d5ta10351g","DOIUrl":"https://doi.org/10.1039/d5ta10351g","url":null,"abstract":"In recent years, organic mixed conducting polymers and small systems have shown great potential in bioelectronics, neuromorphic devices and transient electronics. Current mixed conducting materials are mostly derived from pre-existing semiconductors functionalised with polar ethylene glycol side chains; however, these materials still exhibit limited biocompatibility and degradability. Here, we develop a computational/in silico screening pipeline to investigate the potential of bioinspired building blocks as next-generation materials for organic mixed ionic-electronic conductors (OMIECs). Leveraging sustainable design principles and predictors for electronic charge transport and aggregation/conformational order, we compare two approaches to discover potential new mixed conductors: a computational funnel and a genetic algorithm. We apply and evaluate both approaches against a chemical design space created by matching conjugated fragments from the literature on organic semiconductors, hydrolysable linkers and bioinspired fragments, for a total of almost 25000 unique combinations. Our study demonstrates that, despite the limited chemical diversity of our dataset, both approaches successfully discover many potential donor-linker-acceptor (D-L-A) systems with promising features, namely: low HOMO-LUMO gap, high inter-ring planarity, and low reorganisation energy. We then down-select a few D-L-A systems and symmetrically extend their conjugation to obtain small-molecule prototypes, which show competitive reorganisation energies (as low as 123 meV). We propose that this workflow could be applied to larger datasets and tailored to discover novel chemical motifs for OMIECs and other applications.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"44 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li-doped Mg2Sn thin films are promising p-type thermoelectrics, as Li is among the most effective acceptors, yet their impact on defect chemistry, phase stability, and transport remains poorly understood. Here, low-temperature annealing is shown to passivate Li-induced defects and stabilize electrical transport in epitaxial Mg2-xLixSn (0 ≤ x ≤ 0.10) thin films grown by molecular beam epitaxy. X-ray diffraction and electron microscopy reveal that Li incorporation produces Sn-rich precipitates from deviation from the 2:1 of Mg:Sn stoichiometry, which are partially dissolved after annealing. Depth-resolved positron annihilation spectroscopy indicates a reduction of Mg-vacancy-type defects at moderate Li content, while Hall measurements show decreased hole concentrations and enhanced mobilities, consistent with reduced ionized-impurity scattering. As-grown films exhibit Seebeck coefficients of 40–70 µV K-1 at room temperature, which increase to ~200–250 µV K-1 after annealing, accompanied by suppression of cycle-to-cycle drift. The optimized films achieve an exceptional peak power factor of ~2.4×10-3 Wm-1K-2 at the relatively low temperature of 350 K. Thermal conductivity, measured at room temperature, confirms that defect-engineered films retain strong phonon scattering after annealing, yielding zT≈0.25, surpassing prior p-type Mg2Sn epitaxial thin films. A microfabricated π-type thermoelectric generator using Li-doped Mg2Sn p-legs delivers higher open-circuit voltage than a Mg2Sn(Ge) benchmark with comparable output power, demonstrating the practical viability of the processed films.
{"title":"Defect Passivation by Annealing Enables Stable Transport in Li-Doped Mg2Sn Epitaxial Films for Microfabricated Thermoelectric Devices","authors":"Kenneth Magallon Senados, Takashi Aizawa, Isao Ohkubo, Masayuki Murata, Takahiro Baba, Akihiko Ohi, Akira Uedono, Takeaki Sakurai, Takao Mori","doi":"10.1039/d5ta09301e","DOIUrl":"https://doi.org/10.1039/d5ta09301e","url":null,"abstract":"Li-doped Mg<small><sub>2</sub></small>Sn thin films are promising p-type thermoelectrics, as Li is among the most effective acceptors, yet their impact on defect chemistry, phase stability, and transport remains poorly understood. Here, low-temperature annealing is shown to passivate Li-induced defects and stabilize electrical transport in epitaxial Mg<small><sub>2-x</sub></small>Li<small><sub>x</sub></small>Sn (0 ≤ x ≤ 0.10) thin films grown by molecular beam epitaxy. X-ray diffraction and electron microscopy reveal that Li incorporation produces Sn-rich precipitates from deviation from the 2:1 of Mg:Sn stoichiometry, which are partially dissolved after annealing. Depth-resolved positron annihilation spectroscopy indicates a reduction of Mg-vacancy-type defects at moderate Li content, while Hall measurements show decreased hole concentrations and enhanced mobilities, consistent with reduced ionized-impurity scattering. As-grown films exhibit Seebeck coefficients of 40–70 µV K<small><sup>-1</sup></small> at room temperature, which increase to ~200–250 µV K<small><sup>-1</sup></small> after annealing, accompanied by suppression of cycle-to-cycle drift. The optimized films achieve an exceptional peak power factor of ~2.4×10<small><sup>-3</sup></small> Wm<small><sup>-1</sup></small>K<small><sup>-2</sup></small> at the relatively low temperature of 350 K. Thermal conductivity, measured at room temperature, confirms that defect-engineered films retain strong phonon scattering after annealing, yielding zT≈0.25, surpassing prior p-type Mg<small><sub>2</sub></small>Sn epitaxial thin films. A microfabricated π-type thermoelectric generator using Li-doped Mg<small><sub>2</sub></small>Sn p-legs delivers higher open-circuit voltage than a Mg<small><sub>2</sub></small>Sn(Ge) benchmark with comparable output power, demonstrating the practical viability of the processed films.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"176 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zheng Zhu, Zhanglong Xia, Yue Hou, Wei Cao, Xiaolong Sun, Chang Li, Qianfeng Ding, Wenjie Zhou, Ziyan Jiang, Han Tang, Lai Wei, Cheng Lei, Ziyu Wang
Wearable thermoelectric devices (WTEDs) have garnered significant interest for applications in personal thermal management and energy harvesting from the human body. Nevertheless, a major limitation hindering their performance is inadequate heat dissipation. To overcome this issue, this study introduces an integrated WTED architecture featuring a flexible finned heat sink based on a phase change material (PCM), which is structurally integrated with the thermoelectric unit. The heat sink is composed of epoxy-encapsulated paraffin PCM doped with high-thermal-conductivity aluminum nitride (AlN) additives, significantly enhancing the composite's effective thermal conductivity and overall thermal management capability. Experimental results validate the efficacy of this integrated design: at a temperature difference of 30 K, the device delivers an open-circuit voltage of 239.0 mV and a power output of 9212.85 µW, corresponding to a 1386% enhancement compared to a system without the heat sink. Moreover, the integrated device demonstrates markedly improved conversion efficiency even under low temperature gradients (<10 K), rendering it highly suitable for integration with boosting circuits in wearable electronics. Based on heat transfer optimization, this device achieves portable wearable cooling without fans or liquid cooling assistance. It provides up to a 4.4 °C skin temperature drop and maintains a temperature below body temperature for over 600 s. This work presents an effective, fan- and liquid-free thermal management solution with promising applications in small portable electronics and personalized cooling.
{"title":"A high-performance wearable thermoelectric device with epoxy resin/PA/AlN composite heat sink","authors":"Zheng Zhu, Zhanglong Xia, Yue Hou, Wei Cao, Xiaolong Sun, Chang Li, Qianfeng Ding, Wenjie Zhou, Ziyan Jiang, Han Tang, Lai Wei, Cheng Lei, Ziyu Wang","doi":"10.1039/d5ta07253k","DOIUrl":"https://doi.org/10.1039/d5ta07253k","url":null,"abstract":"Wearable thermoelectric devices (WTEDs) have garnered significant interest for applications in personal thermal management and energy harvesting from the human body. Nevertheless, a major limitation hindering their performance is inadequate heat dissipation. To overcome this issue, this study introduces an integrated WTED architecture featuring a flexible finned heat sink based on a phase change material (PCM), which is structurally integrated with the thermoelectric unit. The heat sink is composed of epoxy-encapsulated paraffin PCM doped with high-thermal-conductivity aluminum nitride (AlN) additives, significantly enhancing the composite's effective thermal conductivity and overall thermal management capability. Experimental results validate the efficacy of this integrated design: at a temperature difference of 30 K, the device delivers an open-circuit voltage of 239.0 mV and a power output of 9212.85 µW, corresponding to a 1386% enhancement compared to a system without the heat sink. Moreover, the integrated device demonstrates markedly improved conversion efficiency even under low temperature gradients (<10 K), rendering it highly suitable for integration with boosting circuits in wearable electronics. Based on heat transfer optimization, this device achieves portable wearable cooling without fans or liquid cooling assistance. It provides up to a 4.4 °C skin temperature drop and maintains a temperature below body temperature for over 600 s. This work presents an effective, fan- and liquid-free thermal management solution with promising applications in small portable electronics and personalized cooling.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"8 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of solid-state proton conductors that operate efficiently across a wide temperature range, from sub-zero to elevated temperatures, remains a significant challenge, hindered by the inherent limitations of water-dependent materials. Herein, we introduce heterometallic sulfates into a bimetallic metal-organic gel (M/Zr-FA-xerogel) via a one-pot synthesis, resulting in the formation of a hierarchical proton conduction network. This innovative strategy concurrently addresses the quantity, quality, and connectivity of proton carriers. In this network, structural defects enhance carrier concentration, while sulfate groups establish extensive hydrogen-bonding pathways. Importantly, we demonstrate that the intrinsic Brønsted acidity of defect sites can be rationally tuned by manipulating the electronic structure of the dopant.Specifically, the d 0 electronic configuration of Ti 4+ serves as an effective electron sink, significantly reducing the proton dissociation barrier, which is critical for cryogenic transport. This integrated design culminates in an adaptive conduction mechanism that transitions from being dominated by acid strength at low temperatures to being limited by carrier concentration at high temperatures. As a result, the optimized Ti/Zr-FA-xerogel exhibits an exceptional anhydrous conductivity of 1.9 × 10 -3 S cm -1 at 233 K, surpassing its counterpart by 3 orders of magnitude, and 5.0 × 10 -2 S cm -1 at 433 K. This research not only develops a novel design strategy for proton conductors operable across a wide temperature range, but also elucidates the intricate interplay between electronic structure, defect chemistry, and proton dynamics in amorphous coordination polymers.
由于依赖水的材料的固有局限性，开发在零下到高温的宽温度范围内有效工作的固态质子导体仍然是一个重大挑战。在此，我们通过一锅合成将异金属硫酸盐引入双金属金属有机凝胶（M/Zr-FA-xerogel）中，从而形成了层次化的质子传导网络。这一创新策略同时解决了质子载体的数量、质量和连通性问题。在这个网络中，结构缺陷提高了载流子浓度，而硫酸盐基团建立了广泛的氢键途径。重要的是，我们证明了可以通过操纵掺杂剂的电子结构来合理地调节缺陷位点的固有Brønsted酸度。具体来说，Ti 4+的d0电子构型作为一个有效的电子汇，显著降低了质子解离势垒，这对低温传输至关重要。这种集成设计在自适应传导机制中达到高潮，该机制从低温时的酸强度主导转变为高温时的载流子浓度限制。结果表明，优化后的Ti/ zr - fa -干凝胶在233 K时的无水电导率为1.9 × 10 -3 S cm -1，比同类产品高出3个数量级，在433 K时的无水电导率为5.0 × 10 -2 S cm -1。本研究不仅开发了一种可在宽温度范围内工作的质子导体的新设计策略，而且阐明了非晶配位聚合物中电子结构、缺陷化学和质子动力学之间复杂的相互作用。
{"title":"Engineering Brønsted Acidity in Metal-Organic Gels via d⁰-Electron Configuration for Wide-Temperature Anhydrous Proton Conduction","authors":"Cuiwen Lu, Wenli Wu, Lingfei Li, Feng Zhang, Jiyu Tang, Siyu Sun, Xiaoqin Zou","doi":"10.1039/d5ta08624h","DOIUrl":"https://doi.org/10.1039/d5ta08624h","url":null,"abstract":"The development of solid-state proton conductors that operate efficiently across a wide temperature range, from sub-zero to elevated temperatures, remains a significant challenge, hindered by the inherent limitations of water-dependent materials. Herein, we introduce heterometallic sulfates into a bimetallic metal-organic gel (M/Zr-FA-xerogel) via a one-pot synthesis, resulting in the formation of a hierarchical proton conduction network. This innovative strategy concurrently addresses the quantity, quality, and connectivity of proton carriers. In this network, structural defects enhance carrier concentration, while sulfate groups establish extensive hydrogen-bonding pathways. Importantly, we demonstrate that the intrinsic Brønsted acidity of defect sites can be rationally tuned by manipulating the electronic structure of the dopant.Specifically, the d 0 electronic configuration of Ti 4+ serves as an effective electron sink, significantly reducing the proton dissociation barrier, which is critical for cryogenic transport. This integrated design culminates in an adaptive conduction mechanism that transitions from being dominated by acid strength at low temperatures to being limited by carrier concentration at high temperatures. As a result, the optimized Ti/Zr-FA-xerogel exhibits an exceptional anhydrous conductivity of 1.9 × 10 -3 S cm -1 at 233 K, surpassing its counterpart by 3 orders of magnitude, and 5.0 × 10 -2 S cm -1 at 433 K. This research not only develops a novel design strategy for proton conductors operable across a wide temperature range, but also elucidates the intricate interplay between electronic structure, defect chemistry, and proton dynamics in amorphous coordination polymers.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"1 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Covalent organic frameworks (COFs) have recently emerged as promising platforms for electrocatalytic nitrate reduction to ammonia (NO3RR), yet most reported systems are limited to two-dimensional architectures. Herein, we present TU-82, a structurally distinct 3D COF featuring an intricate [8 + 2]-connected bcu topology derived from the reticulation of an octatopic D2h-symmetric tetragonal prism node and a C2-symmetric bipyridyl linker. TU-82 exhibits high crystallinity, permanent porosity, and robust structural integrity, enabling precise postsynthetic metalation at bipyridyl coordination sites to yield catalytically active TU-82-Fe and TU-82-Cu frameworks. Among them, TU-82-Fe demonstrates superior NO3RR performance, delivering a faradaic efficiency (FE) of 88.1% at −0.6 V (RHE) and an ammonia yield rate of 2.87 mg h−1 cm−2 at −0.8 V (RHE), together with a turnover frequency of 7.2 h−1 and excellent operational stability. Density functional theory calculations reveal that the enhanced activity of TU-82-Fe originates from a lower energy barrier (0.354 eV) for the rate-determining NO* → NHO* step along the NHO-mediated reaction pathway. This work pioneers a structural blueprint for deploying 3D COFs in electrocatalysis, fostering deeper insights into framework-controlled reactivity and offering new routes to sustainable nitrate management.
共价有机框架（COFs）最近成为电催化硝酸还原氨（NO3RR）的有前途的平台，但大多数报道的系统仅限于二维结构。在这里，我们提出了TU-82，一种结构独特的3D COF，具有复杂的[8 + 2]连接的bcu拓扑，该拓扑由八位d2h对称的四方棱镜节点和c2对称的联吡啶连接体组成。TU-82具有高结晶度、永久孔隙度和坚固的结构完整性，能够在联吡啶配位位点进行精确的合成后金属化，生成具有催化活性的TU-82- fe和TU-82- cu框架。其中，TU-82-Fe表现出优异的NO3RR性能，在- 0.6 V （RHE）下，faradaic效率（FE）为88.1%，在- 0.8 V （RHE）下，氨产率为2.87 mg h - 1 cm - 2，周转率为7.2 h - 1，运行稳定性良好。密度泛函理论计算表明，TU-82-Fe活性的增强源于在NHO介导的反应途径中，NO*→NHO*这一决定速率的步骤具有较低的能垒（0.354 eV）。这项工作开创了在电催化中部署3D COFs的结构蓝图，促进了对框架控制反应性的更深入了解，并为可持续的硝酸盐管理提供了新的途径。
{"title":"Efficient ammonia synthesis via electrocatalytic nitrate reduction over a [8 + 2]-connected three-dimensional metal-bipyridine covalent organic framework","authors":"Tsukasa Irie, Ayumu Kondo, Kai Sun, Kohki Sasaki, Mika Nozaki, Shiho Tomihari, Kotaro Sato, Tokuhisa Kawawaki, Yu Zhao, Saikat Das, Yuichi Negishi","doi":"10.1039/d5ta07989f","DOIUrl":"https://doi.org/10.1039/d5ta07989f","url":null,"abstract":"Covalent organic frameworks (COFs) have recently emerged as promising platforms for electrocatalytic nitrate reduction to ammonia (NO<small><sub>3</sub></small>RR), yet most reported systems are limited to two-dimensional architectures. Herein, we present TU-82, a structurally distinct 3D COF featuring an intricate [8 + 2]-connected <strong>bcu</strong> topology derived from the reticulation of an octatopic <em>D</em><small><sub>2h</sub></small>-symmetric tetragonal prism node and a <em>C</em><small><sub>2</sub></small>-symmetric bipyridyl linker. TU-82 exhibits high crystallinity, permanent porosity, and robust structural integrity, enabling precise postsynthetic metalation at bipyridyl coordination sites to yield catalytically active TU-82-Fe and TU-82-Cu frameworks. Among them, TU-82-Fe demonstrates superior NO<small><sub>3</sub></small>RR performance, delivering a faradaic efficiency (FE) of 88.1% at −0.6 V (RHE) and an ammonia yield rate of 2.87 mg h<small><sup>−1</sup></small> cm<small><sup>−2</sup></small> at −0.8 V (RHE), together with a turnover frequency of 7.2 h<small><sup>−1</sup></small> and excellent operational stability. Density functional theory calculations reveal that the enhanced activity of TU-82-Fe originates from a lower energy barrier (0.354 eV) for the rate-determining NO* → NHO* step along the NHO-mediated reaction pathway. This work pioneers a structural blueprint for deploying 3D COFs in electrocatalysis, fostering deeper insights into framework-controlled reactivity and offering new routes to sustainable nitrate management.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"12 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing efficient energy storage systems that capture and convert CO2 is critical for mitigating carbon emissions. Here, we report a Na–CO2 battery with ruthenium dioxide (RuO2) cathode catalysts and propane-1,3-diamine (PDA) as an electrolyte additive to enhance CO2 capture and conversion efficiency. The integration of CO2 adsorption and electrochemical reduction facilitates activation of the inert CO2 molecule and circumvents gas–solid–liquid ternary-phase reactions at the interface. We employed density functional theory (DFT) calculations to systematically unravel the reaction mechanisms and energetics governing CO2 reduction, both with and without PDA. Our results reveal an energetically favorable pathway toward the formation of Na2CO3 and C as final discharge products, rather than sodium oxalate (Na2C2O4). The CO2–amine adduct facilitates charge transfer from PDA to CO2, which results in activation of CO2. The kinetics of CO2 conversion and regeneration of PDA were found to be significantly enhanced on the RuO2 surface compared to the bulk electrolyte. More importantly, pre-activation of CO2via the amine–CO2 adduct lowers the total overpotential to 2.44 V, compared to 3.13 V without PDA. This study provides fundamental insights into CO2 electroreduction in Na–CO2 batteries and underscores the promise of electrolyte engineering for sustainable CO2 utilization and high-performance energy storage.
{"title":"Mechanistic insights into CO2 capture and electrochemical conversion in nonaqueous Na–CO2 batteries","authors":"Rahul Jayan, Satheesh Mani, Md Mahbubul Islam","doi":"10.1039/d5ta09674j","DOIUrl":"https://doi.org/10.1039/d5ta09674j","url":null,"abstract":"Developing efficient energy storage systems that capture and convert CO<small><sub>2</sub></small> is critical for mitigating carbon emissions. Here, we report a Na–CO<small><sub>2</sub></small> battery with ruthenium dioxide (RuO<small><sub>2</sub></small>) cathode catalysts and propane-1,3-diamine (PDA) as an electrolyte additive to enhance CO<small><sub>2</sub></small> capture and conversion efficiency. The integration of CO<small><sub>2</sub></small> adsorption and electrochemical reduction facilitates activation of the inert CO<small><sub>2</sub></small> molecule and circumvents gas–solid–liquid ternary-phase reactions at the interface. We employed density functional theory (DFT) calculations to systematically unravel the reaction mechanisms and energetics governing CO<small><sub>2</sub></small> reduction, both with and without PDA. Our results reveal an energetically favorable pathway toward the formation of Na<small><sub>2</sub></small>CO<small><sub>3</sub></small> and C as final discharge products, rather than sodium oxalate (Na<small><sub>2</sub></small>C<small><sub>2</sub></small>O<small><sub>4</sub></small>). The CO<small><sub>2</sub></small>–amine adduct facilitates charge transfer from PDA to CO<small><sub>2,</sub></small> which results in activation of CO<small><sub>2</sub></small>. The kinetics of CO<small><sub>2</sub></small> conversion and regeneration of PDA were found to be significantly enhanced on the RuO<small><sub>2</sub></small> surface compared to the bulk electrolyte. More importantly, pre-activation of CO<small><sub>2</sub></small> <em>via</em> the amine–CO<small><sub>2</sub></small> adduct lowers the total overpotential to 2.44 V, compared to 3.13 V without PDA. This study provides fundamental insights into CO<small><sub>2</sub></small> electroreduction in Na–CO<small><sub>2</sub></small> batteries and underscores the promise of electrolyte engineering for sustainable CO<small><sub>2</sub></small> utilization and high-performance energy storage.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"90 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alkaline exchange membrane water electrolysis (AEMWE) is critical for advancing next-generation water electrolysis technologies. Development of cost-effective and durable bifunctional electrocatalysts and chemically robust anion exchange membranes (AEMs), which are the key components for AEMWE, are essential. Herein, we report the rational design of a phosphorus-doped trimetallic oxide heterostructure (PhosTriOx) as a highly active and stable bifunctional catalyst and alkaline stable crosslinked p-methylstyrene-based AEM (Styrion AEM) for alkaline water splitting. The optimized PhosTriO7 catalyst exhibits hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity, requiring overpotentials of 180 mV and 410 mV at 50 mA cm−2, respectively. The Styrion AEM exhibits an ionic conductivity of 51.5 mS cm−1 at 90 °C, an ion exchange capacity (IEC) of 0.85 meq. g−1, and a water uptake of 23–25%, along with long-term alkaline stability. When integrated into a membrane electrode assembly (MEA), the PhosTriO7–AEM system achieved a current density of 1.6 A cm−2 at 2.0 V, surpassing that of Pt/C- and RuOx-based MEAs, and maintained stable operation at 1.82 V at 1 A cm−2 for 250 h with negligible degradation. This work introduces a new material–membrane–device framework and demonstrates that phosphorus-modulated heterostructures synergized with chemically durable AEMs can compete with or surpass noble-metal benchmarks in durability and system-level performance, paving the way toward scalable and sustainable hydrogen production.
碱性交换膜电解（AEMWE）是推进下一代电解技术的关键技术。开发具有成本效益和耐用性的双功能电催化剂和化学稳定性强的阴离子交换膜（AEMs）是AEMWE的关键组成部分。本文报道了一种合理设计的磷掺杂三金属氧化物异质结构（PhosTriOx）作为高活性和稳定的双功能催化剂和碱性稳定交联对甲基苯乙烯基AEM （Styrion AEM）用于碱性水裂解。优化后的PhosTriO7催化剂具有析氢反应（HER）和析氧反应（OER）活性，在50 mA cm−2下分别需要180 mV和410 mV的过电位。Styrion AEM在90°C时的离子电导率为51.5 mS cm−1，离子交换容量（IEC）为0.85 meq。G−1，吸水率为23-25%，长期碱性稳定。当集成到膜电极组件（MEA）中时，PhosTriO7-AEM系统在2.0 V下实现了1.6 a cm - 2的电流密度，超过了Pt/C-和基于ruox的MEAs，并且在1 a cm - 2下保持1.82 V的稳定工作250 h，几乎没有退化。这项工作介绍了一种新的材料-膜-器件框架，并证明了磷调制异质结构与化学耐用的AEMs协同作用可以在耐用性和系统级性能方面与贵金属基准竞争或超越，为可扩展和可持续的氢气生产铺平了道路。
{"title":"High-performance alkaline water electrolysis: a membrane–catalyst–device integrated paradigm","authors":"Shubham Mishra, Sarthak Mishra†, Vartika Sharma†, Debashish Sarkar, Vaibhav Kulshrestha","doi":"10.1039/d5ta08482b","DOIUrl":"https://doi.org/10.1039/d5ta08482b","url":null,"abstract":"Alkaline exchange membrane water electrolysis (AEMWE) is critical for advancing next-generation water electrolysis technologies. Development of cost-effective and durable bifunctional electrocatalysts and chemically robust anion exchange membranes (AEMs), which are the key components for AEMWE, are essential. Herein, we report the rational design of a phosphorus-doped trimetallic oxide heterostructure (PhosTriO<em>x</em>) as a highly active and stable bifunctional catalyst and alkaline stable crosslinked <em>p</em>-methylstyrene-based AEM (Styrion AEM) for alkaline water splitting. The optimized PhosTriO7 catalyst exhibits hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity, requiring overpotentials of 180 mV and 410 mV at 50 mA cm<small><sup>−2</sup></small>, respectively. The Styrion AEM exhibits an ionic conductivity of 51.5 mS cm<small><sup>−1</sup></small> at 90 °C, an ion exchange capacity (IEC) of 0.85 meq. g<small><sup>−1</sup></small>, and a water uptake of 23–25%, along with long-term alkaline stability. When integrated into a membrane electrode assembly (MEA), the PhosTriO7–AEM system achieved a current density of 1.6 A cm<small><sup>−2</sup></small> at 2.0 V, surpassing that of Pt/C- and RuO<small><sub><em>x</em></sub></small>-based MEAs, and maintained stable operation at 1.82 V at 1 A cm<small><sup>−2</sup></small> for 250 h with negligible degradation. This work introduces a new material–membrane–device framework and demonstrates that phosphorus-modulated heterostructures synergized with chemically durable AEMs can compete with or surpass noble-metal benchmarks in durability and system-level performance, paving the way toward scalable and sustainable hydrogen production.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"94 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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