Decoding Molten Salt-Mediated Crystallization Achieves Controllable Transformation of Heptazine→Triazine for...

Area of Science:

• Materials Science
• Catalysis
• Crystallization Science

Background:

• Molten salt synthesis is a versatile method for catalyst fabrication.
• Limited mechanistic understanding of molten salt crystallization hinders rational catalyst design.

Purpose of the Study:

• To elucidate the intrinsic mechanism of molten salt-mediated crystal growth.
• To demonstrate controllable synthesis of poly(heptazine imide) (PHI) and poly(triazine imide) (PTI) homojunctions.

Main Methods:

• Investigated crystallization mechanisms using poly(heptazine imide) (PHI) and poly(triazine imide) (PTI) as model systems.
• Controlled salt template solidification via cooling programs.
• Fabricated Ni-decorated PHI/PTI homojunctions through ion exchange.

Main Results:

• Salt template solidification state dictates structural and morphological transformations.
• Achieved controllable synthesis of PHI/PTI homojunctions with defined morphologies (nanorods and hexagonal prisms).
• Ni-decorated homojunctions exhibited Z-scheme charge transfer, enhancing charge separation and redox ability.

Conclusions:

• The study deepens the understanding of molten salt-mediated crystallization.
• Demonstrated a pathway for fabricating high-performance catalysts by manipulating crystallization.
• The Ni-decorated PHI/PTI homojunction showed significantly enhanced photocatalytic CO2 reduction activity.