A metal-free electrified membrane (EM) containing unmodified carbon nanotubes (CNTs) was used to achieve efficient nitrate reduction in drinking water. The EM, with a nanoporous structure, enabled enhanced nitrate reduction performance comparable to that of metal-based catalysts. The study demonstrated that the EM significantly reduced the diffusion boundary layer, improving mass transport and reaction kinetics. Computational fluid dynamics (CFD) simulations and density functional theory (DFT) calculations revealed that intrinsic defects in CNTs enhanced nitrate adsorption and catalytic activity. The EM showed high nitrate removal efficiency (up to 86.9%) and selectivity for nitrogen gas (N₂), meeting drinking water standards. The EM also exhibited long-term stability and tolerance to environmental interferences. The results highlight the potential of metal-free CNT-EMs as a sustainable and efficient solution for nitrate removal in drinking water treatment, avoiding the need for complex catalyst materials. The study underscores the importance of optimizing mass transport and reaction rates through flow-through operation, enabling effective electrocatalytic nitrate reduction without metal-based catalysts.A metal-free electrified membrane (EM) containing unmodified carbon nanotubes (CNTs) was used to achieve efficient nitrate reduction in drinking water. The EM, with a nanoporous structure, enabled enhanced nitrate reduction performance comparable to that of metal-based catalysts. The study demonstrated that the EM significantly reduced the diffusion boundary layer, improving mass transport and reaction kinetics. Computational fluid dynamics (CFD) simulations and density functional theory (DFT) calculations revealed that intrinsic defects in CNTs enhanced nitrate adsorption and catalytic activity. The EM showed high nitrate removal efficiency (up to 86.9%) and selectivity for nitrogen gas (N₂), meeting drinking water standards. The EM also exhibited long-term stability and tolerance to environmental interferences. The results highlight the potential of metal-free CNT-EMs as a sustainable and efficient solution for nitrate removal in drinking water treatment, avoiding the need for complex catalyst materials. The study underscores the importance of optimizing mass transport and reaction rates through flow-through operation, enabling effective electrocatalytic nitrate reduction without metal-based catalysts.