Heterointerface-engineered SnO2@CoFe layered double hydroxide interfacial catalysts for efficient water dissociation in bipolar membranes

SnO₂@CoFe-LDH heterostructure is designed for water dissociation in bipolar membranes. • Heterointerface promotes charge redistribution and enhances water molecule activation. • BPM with SnO₂@CoFe-LDH achieves a low voltage of 0.75  V at 100 mA cm −2 . • Ultralow water dissociation resistance of 0.12 Ω is attained. • DFT calculations reveal reduced activation energy due to interfacial synergy. Bipolar membranes (BPMs) are important components in electrochemical energy-conversion systems, but their performance is often limited by slow interfacial water dissociation (WD). Herein, a heterostructured SnO 2 @CoFe layered double hydroxide (SnO 2 @CoFe-LDH) catalyst was designed as an efficient interfacial layer to accelerate WD in BPMs. SnO 2 nanoparticles uniformly anchored on CoFe layered double hydroxide (CoFe-LDH) nanosheets form a robust heterointerface that promotes interfacial charge redistribution and enhances water-molecule activation. Owing to this synergistic heterostructure, the resulting BPM delivers a low transmembrane voltage of 0.75  V at 100 mA cm −2 and an ultralow WD resistance of 0.12 Ω, together with stable operation for 72 h at 50 mA cm −2 . Efficient acid-base generation with high current efficiency and low energy consumption is further achieved in bipolar membrane electrodialysis. This work highlights heterointerface engineering as an effective strategy for developing high-performance BPM interfacial catalysts. Download: Download high-res image (73KB) Download: Download full-size image