Single-molecule photocatalytic dynamics at individual defects in two-dimensional layered materials

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Understanding in situ catalytic dynamics at individual structural defects in 2D layered materials is crucial for catalyst design.
• Defect engineering offers a pathway to enhance catalyst performance.
• Current knowledge lacks detailed insights into photocatalytic dynamics at specific defect sites.

Purpose of the Study:

• To quantitatively reveal heterogeneous photocatalytic dynamics and surface diffusion behaviors at individual structural features of 2D layered indium selenide (InSe).
• To investigate the relationship between defect properties, photocatalytic activity, and surface diffusion.
• To guide rational defect engineering for high-performance catalysts.

Main Methods:

• In situ observation of single-molecule trajectories resulting from photocatalytic activities.
• Analysis of photocatalysis at distinct structural features: basal plane, edge, wrinkle, and vacancy in 2D InSe.
• Correlation of catalytic activity and diffusion behaviors with defect structures and layer thickness.

Main Results:

• Highest photocatalytic activity was observed at vacancy sites in four-layer InSe, approximately 30 times higher than on the basal plane.
• More catalytically active defects exhibited lower reactant adsorption strength and slower product dissociation/diffusion rates.
• Distinct dynamic properties were linked to the lattice structures, electronic energy levels of defects, and InSe layer thickness.

Conclusions:

• Defects significantly influence photocatalytic dynamics and surface diffusion in 2D InSe.
• Vacancy sites are highly active catalytic centers in InSe.
• The findings provide fundamental understanding of defect-mediated photocatalysis and inform rational defect engineering strategies for catalyst optimization.