Steering Photoelectrons Excited in Carbon Dots into Platinum Cluster Catalyst for Solar-Driven Hydrogen Production.

In composite photosynthetic systems, one most primary promise is to pursue the effect coupling among light harvesting, charge transfer, and catalytic kinetics. Herein, this study designs the reduced carbon dots (r-CDs) as both photon harvesters and photoelectron donors in combination with the platinum (Pt) clusters and fabricated the function-integrated r-CD/Pt photocatalyst through a photochemical route to control the anchoring of Pt clusters on r-CDs' surface for solar-driven hydrogen (H2) generation. In the obtained r-CD/Pt composite, the r-CDs absorb solar photons and transform them into energetic electrons, which transfer to the Pt clusters with favorable charge separation for H2 evolution reaction (HER). As a result, the efficient coupling of respective natures from r-CDs in photon harvesting and Pt in proton reduction is achieved through well-steered photoelectron transfer in the r-CD/Pt system to cultivate a remarkable and stable photocatalytic H2 evolution activity with an average rate of 681 µmol g-1 h-1. This work integrates two functional components into an effective HER photocatalyst and gains deep insights into the regulation of the function coupling in composite photosynthetic systems.