Photocatalytic performance of few-layer graphitic C₃N₄: enhanced by interlayer coupling

Area of Science:

• Materials Science
• Photocatalysis
• Quantum Chemistry

Background:

• Van der Waals interlayer coupling is key for tuning properties in 2D materials.
• Research on interlayer coupling effects in photocatalysis, especially excited state dynamics, is emerging.

Purpose of the Study:

• To investigate the impact of interlayer coupling on the photocatalytic hydrogen evolution performance of few-layer graphitic carbon nitride (g-C3N4).
• To elucidate the underlying mechanisms, including electronic transitions and charge transfer dynamics.

Main Methods:

• Many-body perturbation theory calculations.
• Ab initio nonadiabatic molecular dynamics simulations.

Main Results:

• Few-layer g-C3N4 shows superior photocatalytic hydrogen evolution compared to monolayer g-C3N4.
• Interlayer coupling activates electronic transitions near the Fermi level, converting dark to bright excitons and broadening solar light absorption.
• Weakened N-H binding energy via intralayer charge transfer and enhanced activity of reactive sites.
• Photogenerated electrons are localized at reactive sites, increasing catalytic efficiency.

Conclusions:

• Interlayer coupling significantly enhances the photocatalytic hydrogen evolution of few-layer g-C3N4.
• The findings provide insights into designing advanced 2D photocatalysts for efficient solar fuel production.