Theory-Guided Discovery of Ion-Exchanged Poly(heptazine imide) Photocatalysts Using First-Principles Many-Body...

Area of Science:

• Materials Science
• Photocatalysis
• Computational Chemistry

Background:

• Poly(heptazine imides) (PHI) are promising photocatalysts.
• Their application is limited by poor control over electronic properties.

Purpose of the Study:

• To modulate the electronic and photocatalytic properties of PHI.
• To investigate the impact of incorporating metal cations into the PHI framework.

Main Methods:

• Utilized many-body perturbation theory calculations for accurate electronic structure analysis.
• Predicted quasiparticle energies, band gaps, and excitonic properties.
• Synthesized and tested metal-doped PHI (M-PHI) materials.

Main Results:

• Identified specific metal dopants (e.g., Pd, Pt, Cu+) that influence band structures.
• Found that some metal dopants, despite favorable band structures, had limited activity due to forbidden d-d transitions.
• Discovered several M-PHI systems with electronic structures suitable for H2O2 production, H2/O2 evolution, and CO2 reduction.

Conclusions:

• Incorporating specific metal cations into PHI is an effective strategy to tune photocatalytic activity.
• Synthesized M-PHI materials (M=K, Na, Li, Ca, Mg, Zn) showed up to a 4.5-fold increase in H2O2 generation.
• This work provides molecular-level insights for designing next-generation M-PHI photocatalysts.