Atomic-Level Heterometallic Engineering in Single-Crystalline Polyoxometalate-Based MOF for Efficient Solar...

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Molybdenum-based polyoxometalates show promise for solar energy due to delocalized electrons.
• Discrete clusters limit charge mobility to intramolecular hopping, hindering efficient solar energy utilization.

Purpose of the Study:

• To develop a three-dimensional polyoxometalate-based metal-organic framework (MOF) enabling intercluster charge delocalization.
• To enhance photothermal conversion efficiency and explore applications in solar energy utilization.

Main Methods:

• Synthesized a novel 3D polyoxometalate-based MOF, [Zn4MoV9MoVI4O40(mbim)2]n (AHF-Zn4).
• Utilized crystallographic insights and strategic substitution with magnetic metal ions (Co2+, Ni2+, Mn2+) to optimize electron transport.
• Employed X-ray absorption spectroscopy and density functional theory (DFT) for detailed electronic structure analysis.

Main Results:

• The AHF-Zn4 MOF facilitated intercluster charge delocalization, significantly enhancing photothermal conversion.
• Substitution with magnetic metal ions improved electron transport dynamics and nonradiative relaxation rates.
• The AHF-CoZn3 MOF reached ~75 °C under 1 sun irradiation, achieving a stable output power of 1088 mW m-2 when integrated with thermoelectric modules.

Conclusions:

• This work presents a novel strategy for designing high-performance polyoxometalate-based MOF photothermal materials.
• The developed MOF demonstrates significant potential for solar water purification, desalination, and solar thermoelectric power generation.