Constructing Fast Transmembrane Pathways in a Layered Double Hydroxide Nanosheets/Nanoparticles Composite Film for an Inorganic Anion-Exchange Membrane
Constructing Fast Transmembrane Pathways in a Layered Double Hydroxide Nanosheets/Nanoparticles Composite Film for an Inorganic Anion-Exchange Membrane
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在无机阴离子交换膜的层状双氢氧化物纳米片/纳米颗粒复合膜中构建快速跨膜途径
DOI：
10.1021/acsami.2c15764
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发表时间：
2022
影响因子：
9.5
通讯作者：
Ma Renzhi
中科院分区：
文献类型：
--
作者：
Xian Fang;Jia Lulu;Sugahara Yoshiyuki;Xue Hairong;Yamauchi Yusuke;Sasaki Takayoshi;Ma Renzhi
具有高电导率的阴离子交换膜（AEM）对于在碱性环境中实现下一代能量存储和转换系统至关重要，在不使用贵铂族金属催化剂的情况下有望降低成本。层状双氢氧化物（LDH）纳米片具有沿面内方向接近10- 1 S cm-1的高电导率，可作为制备无机固体自组装膜的理想材料。然而，二维各向异性导致沿交叉平面方向的10-6S cm-1的基本上低的电导率，这对实现跨包含重新堆叠的纳米片的膜的快速离子传导构成障碍。在本工作中，复合膜的制备是基于混合/组装微米级LDH纳米片与纳米级LDH血小板（纳米颗粒）通过一个简单的真空过滤过程。与纳米粒子的杂化可以改变LDH纳米片的取向，降低其重排顺序，在复合膜中形成多样化的快速离子传导通路和网络。结果表明，复合材料的跨膜电导率比仅由纳米片堆叠而成的复合材料高出1000倍，在面内和面间两个方向上都达到了10- 2 ~ 10- 1 S cm-1的高电导率。
Anion-exchange membranes (AEMs) with high conductivity are crucial for realizing next-generation energy storage and conversion systems in an alkaline environment, promising a huge advantage in cost reduction without using precious platinum group metal catalysts. Layered double hydroxide (LDH) nanosheets, exhibiting a remarkably high hydroxide ion (OH–) conductivity approaching 10–1S cm–1along the in-plane direction, may be regarded as an ideal candidate material for the fabrication of inorganic solid AEMs. However, two-dimensional anisotropy results in a substantially low conductivity of 10–6S cm–1along the cross-plane direction, which poses a hurdle to achieve fast ion conduction across the membrane comprising restacked nanosheets. In the present work, a composite membrane was prepared based on mixing/assembling micron-sized LDH nanosheets with nanosized LDH platelets (nanoparticles) via a facile vacuum filtration process. The hybridization with nanoparticles could alter the orientation of LDH nanosheets and reduce the restacking order, forming diversified fast ion-conducting pathways and networks in the composite membrane. As a result, the transmembrane conductivity significantly improved up to 1000-fold higher than that composed of restacked nanosheets only, achieving a high conductivity of 10–2to 10–1S cm–1in both in-plane and cross-plane directions.