Reversing electron transfer in a covalent triazine framework for efficient photocatalytic hydrogen evolution

Area of Science:

• Materials Science
• Photocatalysis
• Nanotechnology

Background:

• Covalent triazine-based frameworks (CTFs) are crucial for photocatalytic water splitting.
• Developing efficient CTF systems with non-platinum cocatalysts for hydrogen evolution remains a challenge.

Purpose of the Study:

• To develop a novel one-step phosphidation strategy for CTFs.
• To enhance photocatalytic hydrogen evolution using dicobalt phosphide (Co2P) nanocrystals anchored on CTFs.

Main Methods:

• A one-step phosphidation strategy was employed to bond phosphorus atoms with CTF benzene rings.
• Dicobalt phosphide (Co2P) nanocrystals (∼7 nm) were simultaneously anchored onto the CTFs.
• In situ X-ray photoelectron spectroscopy was used for analysis.

Main Results:

• The developed CTF/Co2P composite exhibited significantly enhanced hydrogen evolution activity (7.6 mmol h−1 g−1) under simulated solar light, over 20 times higher than the CTF alone.
• Strong interfacial P-C bonding and Co2P anchoring reversed charge transfer direction, promoting charge separation and accelerating hydrogen evolution.

Conclusions:

• The rational anchoring of transition-metal phosphides on conjugated polymers is a promising strategy for highly efficient photocatalysts.
• This approach offers a pathway for developing advanced materials for solar fuel production.