Heterojunction Synergized Nanofluidic Ionic Diode for High-Performance Hydrovoltaic Electricity Generation

Area of Science:

• Materials Science
• Energy Harvesting
• Nanotechnology

Background:

• Hydrovoltaic electricity generators (HEGs) offer potential for low-grade environmental energy harvesting.
• Current HEGs face limitations in charge separation, electron trapping, and reverse current loss, hindering performance.

Purpose of the Study:

• To enhance HEG performance by proposing a novel concept synergizing a heterojunction and a nanofluidic ionic diode.
• To overcome the limitations of existing HEG technologies.

Main Methods:

• Fabrication of a SiNWs/ATO heterojunction using atomic layer deposition.
• Integration of a nanofluidic ionic diode using a porous CNT membrane.
• Characterization of the synergistic effects on charge separation and ion transport.

Main Results:

• The SiNWs/ATO HEG achieved a record open-circuit voltage of 1.0 V and short-circuit current density of 71.0 µA·cm⁻².
• A peak power density of 45.8 µW·cm⁻² was recorded, approximately double previous highest values.
• Demonstrated efficient charge separation and selective ion transport through synergistic effects.

Conclusions:

• The developed heterojunction synergized nanofluidic ionic diode concept significantly enhances HEG performance.
• This work provides a new design strategy for high-performance and durable HEGs.
• Mechanistic co-optimization of charge separation and ionic transport was achieved.