Visible-light-driven hydrogen evolution using nitrogen-doped carbon quantum dot-implanted polymer dots as metal-free photocatalysts

Given the photocatalytic properties of semiconducting polymers and carbon quantum dots (CQDs), we report a new structure for a metal-free photocatalytic system with a promising efficiency for hydrogen production through the combination of an organic semiconducting polymer (PFTBTA) and N-doped carbon quantum dots (NCQDs) covered by PS-PEGCOOH to produce heterostructured photocatalysts in the form of polymer dots (Pdots). This design could provide strong interactions between the two materials owing to the space confinement effect in nanometer-sized Pdots. Small particle size NCQDs are easy to insert inside the Pdot, which leads to an increase in the stability of the Pdot structure and enhances the hydrogen evolution rate by approximately 5-fold over that of pure PFTBTA Pdots. The photophysics and the mechanism behind the catalytic activity of our design are investigated by transient absorption measurement, demonstrating the role of NCQDs to enhance the charge separation and the photocatalytic efficiency of the PFTBTA Pdot.

Automated summary

This study presents a metal-free photocatalytic system structure with promising efficiency for hydrogen production by combining an organic semiconducting polymer and N-doped carbon quantum dots to form polymer dots. The design enhances charge separation and photocatalytic efficiency, leading to increased hydrogen evolution rate by approximately 5-fold. Through transient absorption measurement, the role of N-doped carbon quantum dots in enhancing the catalytic activity of the organic semiconducting polymer dots is investigated.