Conjugated Microporous Polymer Nanosheets for Overall Water Splitting Using Visible Light

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Direct water splitting using photocatalysts is a key strategy for producing storable chemical fuels from sunlight.
• Conjugated polymers offer tunable optoelectronic properties, making them attractive alternatives to inorganic semiconductors for photocatalysis.
• Efficient photocatalysts for splitting pure water under visible light remain a significant challenge.

Purpose of the Study:

• To develop and investigate conjugated polymer nanosheets (CMPNs) as efficient photocatalysts for pure water splitting.
• To evaluate the performance of CMPNs under visible light irradiation.
• To explore the potential of organic polymers for solar-fuel generation.

Main Methods:

• Synthesis of 1,3-diyne-linked conjugated microporous polymer nanosheets (CMPNs) via oxidative coupling of terminal alkynes (TEPB and TEB).
• Photocatalytic evaluation of CMPNs for water splitting into H₂ and O₂ under visible light (400 nm).
• First-principles calculations to determine the energetic feasibility of photocatalytic reactions.

Main Results:

• CMPNs efficiently split pure water into stoichiometric amounts of H₂ and O₂ under visible light.
• Apparent quantum efficiencies at 420 nm reached 10.3% (TEPB) and 7.6% (TEB).
• Solar-to-hydrogen conversion efficiency reached 0.6%, surpassing photosynthetic plants.

Conclusions:

• 1,3-diyne-linked CMPNs are highly efficient photocatalysts for pure water splitting under visible light.
• Organic polymers demonstrate significant potential for stable and scalable solar-fuel generation.
• The findings pave the way for advanced organic materials in renewable energy applications.