Engineering Interfacial Built-In Electric Fields via Work Function Matching Enables Photocoupled Osmotic Energy...

Area of Science:

• Materials Science
• Electrochemistry
• Environmental Engineering

Background:

• Osmotic energy conversion utilizes salinity gradients for sustainable electricity generation.
• Saline waste streams offer an underutilized resource for energy recovery and pollutant remediation.

Purpose of the Study:

• To develop an advanced membrane for enhanced osmotic energy conversion and wastewater remediation.
• To investigate the role of built-in electric fields in membrane performance.

Main Methods:

• Fabrication of an asymmetric MoS2/oxygen-doped ZIF-8 membrane (MS-ZIF-A).
• Implementation of work function matching to create an internal electric field (IEF).
• Testing the membrane under various NaCl salinity gradients and simulated industrial wastewater.

Main Results:

• The MS-ZIF-A membrane achieved a peak power density of 9.4 W m⁻² with a 50-fold NaCl gradient.
• The membrane demonstrated power densities up to 30 W m⁻² in wastewater, concurrently degrading organic pollutants.
• Work function engineering effectively enhanced ion transport and energy conversion.

Conclusions:

• Work function engineering is a viable strategy for creating interfacial IEF in asymmetric membranes.
• The developed membrane offers a promising approach for high-performance blue-energy devices.
• This technology presents a pathway for energy-positive treatment of saline wastewater.