Leveraging Asymmetric Hydraulic Behaviors in Janus Electrocatalytic Membranes To Maximize Performance

Janus electrocatalytic membranes (JEMs), with their bifunctional interfaces that enable synergistic multireaction pathways, show great potential for advanced water treatment. This study reveals a novel and critical insight: the inherent asymmetric hydraulic behavior between the feed- and permeate-sides of JEMs fundamentally determines the spatial variations in the electrochemical activity. Importantly, the strategic deployment of active interfaces to leverage this asymmetry maximizes the catalytic performance without requiring additional energy or material input. Herein, we experimentally observed that simply positioning the dominant active interface on the hydraulically advantageous feed-side enhanced pollutant degradation by 4- to 10-fold under identical conditions. Numerical simulations revealed significant asymmetric hydraulic behaviors in convection, bypass, and concentration diffusion between the feed- and permeate-side. This asymmetry resulted in enhanced mass transfer, larger electroactive area, and faster electron transfer on the feed-side. Furthermore, life cycle assessment and environmental life cycle costing analyses demonstrate that rationally positioning active interfaces in JEMs not only enhances performance but also achieves superior environmental sustainability and cost-effectiveness compared to conventional strategies that increase the current density and catalyst loading. In summary, this study presents an innovative and resource-efficient design principle to maximize the performance of JEMs by leveraging their asymmetric hydraulics.