Chen Wanting, Chen Musen, Zhen Dongxing, Li Tiantian, Wu Xuemei, Tang Shuai, Wan Lei, Zhang Shouhai, He Gaohong
State Key Laboratory of Fine Chemicals, Research and Development Center of Membrane Science and Technology, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore.
ACS Appl Mater Interfaces. 2020 Sep 9;12(36):40740-40748. doi: 10.1021/acsami.0c09122. Epub 2020 Aug 25.
A novel sulfated tin oxide solid superacid granular stacked one-dimensional (1D) hollow nanofiber (SO/FSnO) is proposed as a nanofiller in sulfonated poly(phthalazinone ether sulfone ketone) (SPPESK) to manipulate a highly conductive proton nanochannel. It has unique microstructures with an open-end hollow nanofibric morphology and grain-stacked single-layer mesoporous fiber wall, which greatly enlarge the specific surface area and aspect ratio. The diverse acid sites, that is, SO, Sn-OH Brönsted, and Sn Lewis superacids, provide a high concentration of strong acidic proton carriers on the nanofiber surface and dynamically abundant hydrogen bonds for rapid proton transfer and interfacial interactions with -SOH groups in the SPPESK along the 1D hollow nanofiber. As a result, long-range orientated ionic clusters are observed in the SO/FSnO incorporated membrane, leading to simultaneous enhancement of proton conductivity (226.7 mS/cm at 80 °C), mechanical stability (31.4 MPa for the hydrated membrane), fuel permeation resistance, and single-cell performance (936.5 and 147.3 mW/cm for H/O and direct methanol fuel cells, respectively). The superior performance, as compared with that of the zero-dimensional nanoparticle-incorporated membrane, Nafion 115, and previously reported SPPESK-based membranes, suggests a great potential of elaborating superstructural 1D hollow nanofillers for highly conductive proton-exchange membranes.
一种新型的硫酸化氧化锡固体超强酸颗粒堆积的一维（1D）中空纳米纤维（SO/FSnO）被提议作为磺化聚（酞嗪酮醚砜酮）（SPPESK）中的纳米填料，以操控高导电质子纳米通道。它具有独特的微观结构，呈开口端中空纳米纤维形态以及颗粒堆积的单层中孔纤维壁，这极大地增大了比表面积和长径比。多样的酸位点，即SO、Sn-OH布朗斯特酸和Sn路易斯超强酸，在纳米纤维表面提供了高浓度的强酸性质子载体以及动态丰富的氢键，用于质子沿1D中空纳米纤维快速转移以及与SPPESK中的-SOH基团进行界面相互作用。结果，在掺入SO/FSnO的膜中观察到了长程取向的离子簇，从而导致质子传导率（80℃时为226.7 mS/cm）、机械稳定性（水合膜为31.4 MPa）、燃料渗透抗性以及单电池性能（氢/氧燃料电池和直接甲醇燃料电池分别为936.5和147.3 mW/cm）同时得到提高。与掺入零维纳米颗粒的膜、Nafion 115以及先前报道的基于SPPESK的膜相比，这种优异的性能表明精心设计超结构1D中空纳米填料用于高导电质子交换膜具有巨大潜力。
