Scalable Mixed-Dimensional Nanogenerator for the Sunlight-Driven Water-Energy Nexus

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Achieving net-zero emissions necessitates advanced solar-driven technologies for simultaneous clean water and energy production.
• Current sustainable solutions often lack the efficiency and scalability required for widespread adoption.

Purpose of the Study:

• To develop and characterize a scalable plasma-engineered solar thermal matrix (STM) for efficient solar-driven water purification and energy harvesting.
• To investigate the synergistic effects of integrated graphene quantum dots (GQDs), MXene nanosheets, and a chitosan framework within the STM.

Main Methods:

• Utilized microplasma-assisted synthesis to create hierarchical porous architectures with angstrom-scale nanochannels in the STM.
• Integrated graphene quantum dots (GQDs), MXene nanosheets, and a chitosan-based framework into the solar thermal matrix.
• Evaluated photothermal conversion efficiency, solar steam generation rate, streaming potential generation in seawater, and long-term performance under solar exposure.

Main Results:

• The optimized STM achieved a high photothermal conversion efficiency of 95.7% and a solar steam generation rate of 4.2 kg m^-2 h^-1.
• Demonstrated streaming potentials up to 200 mV in seawater due to negatively charged nanochannels and embedded GQDs.
• Outdoor trials confirmed daily desalination of approximately 30 kg m^-2 and stable electrical output of ~127 mV over 9 hours.

Conclusions:

• The developed STM is a versatile and durable platform for decentralized water purification and renewable energy harvesting.
• The study provides critical insights into designing multifunctional, mixed-dimensional nanomaterials for integrated solar-driven systems.
• This technology offers a promising pathway towards sustainable solutions for clean water and energy needs.