Constructing effective ion channels in anion exchange membranes via exfoliated nanosheets towards improved conductivity for alkaline fuel cells

A series of quaternized polysulfone (QPS)-based composite membranes containing various amounts of functionalized graphitic carbon nitride (f-g-C3N4) nanosheets were synthesized. The synergistic effects of the incorporated nanosheets were investigated on a variety of membrane properties for alkaline fuel cell application, such as hydroxyl ion conductivity, swelling ratio, water uptake, chemical stability, and cell performance. The well-interacting architecture of the f-g-C3N4 nanosheets containing multiple hydrophilic sites was the main reason for the enhanced hydroxide ion conductivity of the membrane. The QPS-CN-5 membrane showed a high hydroxide ion conductivity of 16-37 mS cm(-1) in a temperature range from room temperature to 80 degrees C because of the highly interlocked ionic domains of the porous tris-triazine units in the f-g-C3N4 nanosheets. The single-cell test of QPS-CN-5 exhibited a maximum power density of 77 mW cm(-2).

Automated summary

A series of quaternized polysulfone (QPS)-based composite membranes containing functionalized graphitic carbon nitride (f-g-C3N4) nanosheets were synthesized and studied for alkaline fuel cell application. The nanosheets enhanced the hydroxide ion conductivity of the membrane due to their well-interacting architecture with multiple hydrophilic sites. The QPS-CN-5 membrane showed a high hydroxide ion conductivity and a maximum power density of 77 mW cm(-2) during single-cell testing.