Simultaneously Promoting Proton Conductivity and Mechanical Stability of SPEEK Membrane by Incorporating Porous g–C<sub>3</sub>N<sub>4</sub>

Proton exchange membranes are widely used in environmentally friendly applications such as fuel cells and electrochemical hydrogen compression. In these applications, an ideal proton exchange membrane should have both excellent proton conductivity and mechanical strength. Polymer proton exchange mem...

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Main Authors: Xiaoyao Wang, Benbing Shi
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Membranes
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Online Access:https://www.mdpi.com/2077-0375/15/7/194
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author Xiaoyao Wang
Benbing Shi
author_facet Xiaoyao Wang
Benbing Shi
author_sort Xiaoyao Wang
collection DOAJ
description Proton exchange membranes are widely used in environmentally friendly applications such as fuel cells and electrochemical hydrogen compression. In these applications, an ideal proton exchange membrane should have both excellent proton conductivity and mechanical strength. Polymer proton exchange membranes, such as sulfonated poly(ether ether ketone) (SPEEK) membranes with high ion exchange capacity, can lead to higher proton conductivity. However, the ionic groups may reduce the interaction between polymer segments, lower the membrane’s mechanical strength, and even cause it to dissolve in water as the temperature exceeds 55 °C. The porous graphitic C<sub>3</sub>N<sub>4</sub> (Pg–C<sub>3</sub>N<sub>4</sub>) nanosheet is an important two–dimensional polymeric carbon–based material and has a high content of –NH<sub>2</sub> and –NH– groups, which can interact with the sulfonic acid groups in the sulfonated SPEEK polymer, form a more continuous proton transfer channel, and inhibit the movement of the polymer segment, leading to higher proton conductivity and mechanical strength. In this study, we found that a SPEEK membrane containing 3% Pg–C<sub>3</sub>N<sub>4</sub> nanosheets achieves the optimized proton conductivity of 138 mS/cm (80 °C and 100% RH) and a mechanical strength of 74.1 MPa, improving both proton conductivity and mechanical strength by over 50% compared to the SPEEK membrane.
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spelling doaj-art-d15c35ed2f654ddbb90a475eee03c6d42025-08-20T03:07:55ZengMDPI AGMembranes2077-03752025-06-0115719410.3390/membranes15070194Simultaneously Promoting Proton Conductivity and Mechanical Stability of SPEEK Membrane by Incorporating Porous g–C<sub>3</sub>N<sub>4</sub>Xiaoyao Wang0Benbing Shi1Guangdong Water Co., Ltd., Shenzhen 518021, ChinaCollege of Food Quality and Engineering, Nanning University, Nanning 530000, ChinaProton exchange membranes are widely used in environmentally friendly applications such as fuel cells and electrochemical hydrogen compression. In these applications, an ideal proton exchange membrane should have both excellent proton conductivity and mechanical strength. Polymer proton exchange membranes, such as sulfonated poly(ether ether ketone) (SPEEK) membranes with high ion exchange capacity, can lead to higher proton conductivity. However, the ionic groups may reduce the interaction between polymer segments, lower the membrane’s mechanical strength, and even cause it to dissolve in water as the temperature exceeds 55 °C. The porous graphitic C<sub>3</sub>N<sub>4</sub> (Pg–C<sub>3</sub>N<sub>4</sub>) nanosheet is an important two–dimensional polymeric carbon–based material and has a high content of –NH<sub>2</sub> and –NH– groups, which can interact with the sulfonic acid groups in the sulfonated SPEEK polymer, form a more continuous proton transfer channel, and inhibit the movement of the polymer segment, leading to higher proton conductivity and mechanical strength. In this study, we found that a SPEEK membrane containing 3% Pg–C<sub>3</sub>N<sub>4</sub> nanosheets achieves the optimized proton conductivity of 138 mS/cm (80 °C and 100% RH) and a mechanical strength of 74.1 MPa, improving both proton conductivity and mechanical strength by over 50% compared to the SPEEK membrane.https://www.mdpi.com/2077-0375/15/7/194proton exchange membranesulfonated poly(ether ether ketone)g–C<sub>3</sub>N<sub>4</sub>
spellingShingle Xiaoyao Wang
Benbing Shi
Simultaneously Promoting Proton Conductivity and Mechanical Stability of SPEEK Membrane by Incorporating Porous g–C<sub>3</sub>N<sub>4</sub>
Membranes
proton exchange membrane
sulfonated poly(ether ether ketone)
g–C<sub>3</sub>N<sub>4</sub>
title Simultaneously Promoting Proton Conductivity and Mechanical Stability of SPEEK Membrane by Incorporating Porous g–C<sub>3</sub>N<sub>4</sub>
title_full Simultaneously Promoting Proton Conductivity and Mechanical Stability of SPEEK Membrane by Incorporating Porous g–C<sub>3</sub>N<sub>4</sub>
title_fullStr Simultaneously Promoting Proton Conductivity and Mechanical Stability of SPEEK Membrane by Incorporating Porous g–C<sub>3</sub>N<sub>4</sub>
title_full_unstemmed Simultaneously Promoting Proton Conductivity and Mechanical Stability of SPEEK Membrane by Incorporating Porous g–C<sub>3</sub>N<sub>4</sub>
title_short Simultaneously Promoting Proton Conductivity and Mechanical Stability of SPEEK Membrane by Incorporating Porous g–C<sub>3</sub>N<sub>4</sub>
title_sort simultaneously promoting proton conductivity and mechanical stability of speek membrane by incorporating porous g c sub 3 sub n sub 4 sub
topic proton exchange membrane
sulfonated poly(ether ether ketone)
g–C<sub>3</sub>N<sub>4</sub>
url https://www.mdpi.com/2077-0375/15/7/194
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AT benbingshi simultaneouslypromotingprotonconductivityandmechanicalstabilityofspeekmembranebyincorporatingporousgcsub3subnsub4sub