Work

Orderly stacked 3D-nanohelices interlayer boosts performance of reverse osmosis membranes for effective water purification

Year: 2025

Type: article

Abstract: Reverse osmosis (RO) membrane with high water permeance and selectivity is highly desirable for effective water purification. However, current RO membranes are typically limited by the trade-off phenomenon between water permeance and selectivity. In this study, we first synthesized a 3D nanohelices with nanoscale gaps spacing, then constructed high-performance RO membranes by incorporating the 3D nanohelices as an interlayer. The 3D nanohelices-interlayered RO membrane exhibited ultra-high pure water permeance (∼3.6 L h −1 m −2 ·bar −1 ) and outstanding NaCl rejection (∼98.7 %), outperformed the performance of current available RO membranes. Importantly, the 3D nanohelices-interlayered RO membrane demonstrated superior removal of neutral small-molecule nitrosamine pollutants (∼69.9 %, ∼87.6 %, ∼89.9 % and∼95.0 %), including N -nitrosodimethylamine, N -nitrosomethylethylamine, N -nitrosopyrrolidine, and N -nitrosodiethylamine, compared to the control (∼46.8 %, ∼79.0 %, ∼86.7 % and ∼93.2 %). We revealed that the gutter effect induced by the 3D nanohelices, which shortened the water transport pathway (nano-gaps served as transport channels for water molecules), was the primary mechanism behind the enhanced water permeance of the 3D nanohelices-interlayered RO membrane. The steric hindrance effects of the polyamide layer and the nanoscale selective gaps within the 3D nanohelices synergistically governed the RO membrane rejection of salts and small-molecule pollutants. Our study provides a promising strategy for the rational design of RO membranes for highly effective water purification. • 3D-nanohelices interlayer delivers ultra-high RO membrane water permeance. • 3D-nanohelices create nano-gap channels, shortening water transport pathways. • The membrane effectively removes neutral nitrosamine pollutants (95.0 %). • Synergistic steric hindrance and nano-scale gaps ensure selective solute rejection.

Source: Energy & Environmental Sustainability

DOI: 10.1016/j.eesus.2025.02.001