近日，我校化學與化工學院曹麗慧教授團隊圍繞離子型氫鍵有機框架（iHOFs）材料的質(zhì)子傳導及燃料電池應(yīng)用開展了一系列研究工作，在Advanced Functional Materials（IF = 18.5）、Chemical Engineering Journal（IF = 13.3）、ACS Materials Letters（IF = 9.6）期刊上發(fā)表了三篇研究論文，并受邀撰寫電荷輔助iHOFs材料的設(shè)計合成及應(yīng)用的相關(guān)綜述（Chemistry-A European Journal, 2024, 30, e202303580）。
氫鍵有機框架（HOFs）是由有機分子單元通過非共價氫鍵相互作用構(gòu)建而成的晶體，分子間作用力較弱，因此合成和設(shè)計具有超質(zhì)子傳導性和穩(wěn)健性的氫鍵有機框架相對困難。通過酸堿配對策略自組裝的離子氫鍵有機框架（iHOFs），由于具有豐富的氫鍵、強離子鍵以及π-π堆積等相互作用使之成為可能，結(jié)構(gòu)中豐富的氫鍵為質(zhì)子提供了獨特的輸運路徑。同時，iHOFs中的酸堿有機分子可作為質(zhì)子載體或質(zhì)子源，有效地傳輸質(zhì)子，可獲得具有超質(zhì)子導電性的材料。
本文利用聯(lián)苯二磷酸和1,1’-二氨基-4,4’-二聯(lián)吡啶為原料制備了一例大尺寸的三維（3D）氫鍵網(wǎng)絡(luò)結(jié)構(gòu)iHOF-16，該材料具有優(yōu)異的熱穩(wěn)定性和化學穩(wěn)定性，在強酸堿條件下也能保持高結(jié)晶度和堅固的結(jié)構(gòu)。iHOF-16沿a軸、b軸和c軸方向分別具有0.388、5.56×10-3和3.25×10-4 S cm-1的高各向異性質(zhì)子傳導率。利用密度泛函理論（DFT）計算結(jié)果表明質(zhì)子最容易在a軸方向傳輸，從而產(chǎn)生超質(zhì)子傳導率。通過電荷輔助合成策略，為設(shè)計穩(wěn)定的超質(zhì)子導電材料提供了一種可行的方法。
相關(guān)成果以“An Ultra-Robust and 3D Proton Transport Pathways iHOF with Single-Crystal Superprotonic Conductivity Around 0.4 S·cm?1”為題，發(fā)表在Advanced Functional Materials（IF = 18.5）上。陜西科技大學為論文第一通訊單位，化學與化工學院2023級博士研究生曹蕭杰為該論文的第一作者，曹麗慧教授為第二作者和論文唯一通訊作者。
本工作以1,3,5-三（4-膦酸基苯基）苯與鹽酸胍為原料，在二甲胺調(diào)節(jié)的作用下，成功制備了兩種iHOFs（即iHOF-14、iHOF-15）。其中，胍陽離子和芳基膦酸陰離子通過電荷輔助氫鍵增強了框架的穩(wěn)定性。由于豐富的氫鍵網(wǎng)絡(luò)，iHOF-14和iHOF-15表現(xiàn)出超過10-2 S·cm-1的質(zhì)子導電性。此外，我們將iHOFs摻雜到Nafion基質(zhì)中，得到了具有更豐富的質(zhì)子傳輸路徑和良好的甲醇阻隔性能的PEM。在100 °C和98% RH下，9%-iHOF-14/Nafion和9%-iHOF-15/Nafion電導率分別達到1.53 × 10-1和1.78 × 10-1 S·cm-1。72 h的甲醇滲透實驗結(jié)果表明，復合膜的甲醇滲透率比重鑄后的Nafion低73.7%。用于DMFCs的混合膜的最大功率密度約為80 mW·cm-2，是重鑄Nafion的1.5倍。這一工作不僅豐富了芳基膦酸鹽iHOFs，而且拓展了用于DMFC的iHOFs/Nafion PEM材料。
相關(guān)成果以“Dimethylamine-tuned guanidinium arylphosphonate iHOFs and superprotonic conduction Nafion hybrid membranes for DMFCs”為題，發(fā)表在Chemical Engineering Journal（IF = 13.3）上。陜西科技大學為論文唯一通訊單位，化學與化工學院2022級博士研究生白向田為該論文的第一作者，曹麗慧教授為論文唯一通訊作者。
本文以六(4-磺酸基苯基)苯和1,1’-二氨基-4,4’-二聯(lián)吡啶為原料合成了具有三維氫鍵網(wǎng)絡(luò)的iHOF-13。穩(wěn)定的iHOF是通過電荷輔助氫鍵相互作用連接，并通過靜電吸引進一步加強。同時，結(jié)晶水分子的存在促進了更廣泛的氫鍵網(wǎng)絡(luò)形成，從而使iHOFs具有超質(zhì)子導電性。具體來說，iHOF-13在98% RH和100 °C下的質(zhì)子電導率為1.3 × 10-1 S·cm-1。iHOF富含質(zhì)子輸運位點，其摻雜到Nafion基體中表現(xiàn)出極高的質(zhì)子電導率（10-1 S·cm-1）和低的甲醇滲透率。在直接甲醇燃料電池中，7.5%-iHOF-13/Nafion復合膜的最大功率密度可達104.7 mW·cm-2，是重鑄Nafion的2.1倍。高性能iHOF的加入有助于增強質(zhì)子傳輸途徑，同時有效抑制甲醇交叉，從而擴大其在燃料電池中的潛在應(yīng)用。
相關(guān)成果以“Arylsulfonate Ionic Hydrogen-Bonded Organic Frameworks Enable Highly Stable and Superprotonic Conductivity for Enhancing Direct Methanol Fuel Cells” 為題，發(fā)表在ACS Materials Letters上（IF = 9.6）上。陜西科技大學為論文唯一通訊單位，化學與化工學院2022級博士研究生白向田為該論文的第一作者，曹麗慧教授為論文唯一通訊作者。
以上研究成果得到國家自然科學基金（22075169）和陜西基礎(chǔ)科學（化學、生物學）研究院科學研究計劃項目（22JHQ026）的支持。
原文鏈接：https://doi.org/10.1002/adfm.202409359
https://doi.org/10.1016/j.cej.2024.150747
https://doi.org/10.1021/acsmaterialslett.4c00953
https://doi.org/10.1002/chem.202303580
新聞小貼士：
附：曹麗慧教授團隊近三年代表性論文：
1. X.-J. Cao, L.-H. Cao*, X.-T. Bai, X.-Y. Hou, H.-Y. Li, An Ultra-Robust and 3D Proton Transport Pathways iHOF with Single Crystal Superprotonic Conductivity Around 0.4 S·cm?1, Adv. Funct. Mater., 2024, 2409359. (IF2023=18.5)
https://doi.org/10.1002/adfm.202409359
2. X.-T. Bai, L.-H. Cao*, X.-Y. Chen, S.-H. Li, J.-H. Zhang, Dimethylamine-tuned guanidinium arylphosphonate iHOFs and superprotonic conduction Nafion hybrid membranes for DMFCs, Chem. Eng. J., 2024, 487, 150747. (IF2023=13.3)
https://doi.org/10.1016/j.cej.2024.150747
3. X.-T. Bai, L.-H. Cao*, F. Zhao, and S.-H. Li, Arylsulfonate Ionic Hydrogen-Bonded Organic Frameworks Enable Highly Stable and Superprotonic Conductivity for Enhancing Direct Methanol Fuel Cells, ACS Materials Lett., 2024, 6, 3351?3357. (IF2023=9.6)
https://doi.org/10.1021/acsmaterialslett.4c00953
4. M.-F. Huang, L.-H. Cao*, and B. Zhou, A solvent-controlled photoresponsive ionic hydrogen-bonded organic framework for encryption applications, Chem. Commun., 2024, 60, 3437–3440. (IF2023=4.3)
https://doi.org/10.1039/D4CC00701H
5. X.-Y. Chen, L.-H.Cao*, X.-T. Bai, and X.-J. Cao, Charge-Assisted Ionic Hydrogen-Bonded Organic Frameworks: Designable and Stabilized Multifunctional Materials, Chem. Eur. J., 2024, 30, e202303580. (Invited Review, IF2023=3.9)
https://doi.org/10.1002/chem.202303580
6. X.-T. Bai, L.-H. Cao*, C. Ji, F. Zhao, X.-Y. Chen, X.-J. Cao, and M.-F. Huang, Ultra-High Proton Conductivity iHOF Based on Guanidinium Arylphosphonate for Proton Exchange Membrane Fuel Cells, Chem. Mater., 2023, 35, 3172?3180. (IF2023=7.2)
https://doi.org/10.1021/acs.chemmater.2c03817
7. X.-Y. Chen, L.-H. Cao*, X.-T. Bai, X.-J. Cao, D. Yang, and Y.-D. Gao, Superprotonic Conductivity of Guanidinium Organosulfonate Hydrogen-Bonded Organic Frameworks with Nanotube-Shaped Proton Transport Channels, Precis. Chem., 2023, 1, 608?615. (新刊無影響因子)
https://doi.org/10.1021/prechem.3c00094
8. F. Zhao, L.-H. Cao*, and C. Ji, Proton conduction of an ionic HOF with multiple water molecules and application as a membrane filler in direct methanol fuel cells, J. Mater. Chem. C, 2023, 11, 15288-15293. (IF2023=5.7)
https://doi.org/10.1039/D3TC03123C
9. X.-Y. Chen, L.-H. Cao*, M.-F. Huang, Y. Yang, Y.-D. Gao, X.-T. Bai, and D. Yang, Water-Induced Single-Crystal to Single-Crystal Transformation of Ionic Hydrogen-Bonded Organic Frameworks with Enhanced Proton Conductivity, Chem. Eur. J., 2023, 29, e202300028. (IF2023=3.9)
https://doi.org/10.1002/chem.202300028
10. X.-T. Bai, L.-H. Cao*, X.-Y. Chen, X.-J. Cao, W.-C. Meng, and K.-Y. Yan, A Sodium-Based Phosphonates Metal?Organic Framework with Superprotonic Conductivity, Cryst. Growth Des., 2023, 23, 8488?8493. (IF2023=3.2)
https://doi.org/10.1021/acs.cgd.3c01102
11. F. Zhao, L.-H. Cao*, X.-T. Bai, X.-Y. Chen, and Z. Yin, Application of Ionic Hydrogen-Bonded Organic Framework Materials in Hybrid Proton Exchange Membranes, Cryst. Growth Des., 2023, 23, 1798?1804. (IF2023=3.2)
https://doi.org/10.1021/acs.cgd.2c01306
12. Y. Yang, X.-Y. Chen, X.-M. Li, F. Zhao, X.-T. Bai and L.-H. Cao*, Enhanced proton conduction of crystalline organic salt hybrid membranes and the performance of fuel cells, Mater. Chem. Front., 2022, 6, 3402–3408. (IF2022=7.0)
https://doi.org/10.1039/D2QM00656A
13. Y.-W. Tang, X.-Y. Chen, F. Zhao, X.-T. Bai, Z. Yin, and L.-H. Cao*, Enhanced Proton Conductivity of an Ionic Hydrogen-Bonded Organic Framework-Embedded Nafion Matrix, Energy Fuels, 2022, 36, 12772?12779. (IF2022=5.3)
https://doi.org/10.1021/acs.energyfuels.2c02520
14. L.-H. Cao*, Y. Yang, X.-H. Tang, X. Wang, and Z. Yin, Substituent Controlled Framework Transformation Based on Solvent-Assisted Linker Exchange, Cryst. Growth Des. 2022, 22, 37-42. (IF2022=3.8) https://doi.org/10.1021/acs.cgd.1c00949
15. X.-Q. Xu, L.-H. Cao*, Y. Yang, F. Zhao, X.-T. Bai, and S.-Q. Zang, Hybrid Nafion Membranes of Ionic Hydrogen-Bonded Organic Framework Materials for Proton Conduction and PEMFC Applications, ACS Appl. Mater. Interfaces 2021, 13, 56566?56574. (IF2021=10.383) https://doi.org/10.1021/acsami.1c15748
16. L.-H. Cao*, X.-Q. Xu, X.-H. Tang, Y. Yang, J. Liu, Z. Yin, S.-Q. Zang, and Y.-M. Ma, Controllable Strategy for Metal?Organic Framework Light-Driven [2 + 2] Cycloaddition Reactions via Solvent-Assisted Linker Exchange, Inorg. Chem. 2021, 60, 2117?2121. (Supplementary Cover, IF2021=5.436)
https://dx.doi.org/10.1021/acs.inorgchem.0c02999
17. X.-Q. Xu, L.-H. Cao*, Y. Yang, X.-T. Bai, F. Zhao, Z.-H. He, Z. Yin, and Y.-M. Ma, Cationic Nonporous Macrocyclic Organic Compounds for Multimedia Iodine Capture, Chem Asian J. 2021, 16, 142?146. (IF2021=4.839)
https://doi.org/10.1002/asia.202001298
（核稿：黃文歡 編輯：王亮）
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