Fabrication

Pathology

Osmosis

Nanotechnology

Reversed electrodialysis

Energy conversion efficiency

Membrane

Forward osmosis

Reverse osmosis

Engineering

Osmotic power

Chemistry

Materials science

Alternative medicine

Desalination

Anodic Aluminum Oxide

Electrodialysis

Chemical engineering

Optoelectronics

Biochemistry

Medicine

Nature Communications

The salinity gradient between seawater and river water is a clean energy source and an alternative solution for the increasing energy demands. A membrane-based reverse electrodialysis technique is a promising strategy to convert osmotic energy to electricity. To overcome the limits of traditional membranes with low efficiency and high resistance, nanofluidic is an emerging technique to promote osmotic energy harvesting. Here, we engineer a high-performance nanofluidic device with a hybrid membrane composed of a silk nanofibril membrane and an anodic aluminum oxide membrane. The silk nanofibril membrane, as a screening layer with condensed negative surface and nanochannels, dominates the ion transport; the anodic aluminum oxide membrane, as a supporting substrate, offers tunable channels and amphoteric groups. Thus, a nanofluidic membrane with asymmetric geometry and charge polarity is established, showing low resistance, high-performance energy conversion, and long-term stability. The system paves avenues for sustainable power generation, water purification, and desalination.

High-performance silk-based hybrid membranes employed for osmotic energy conversion