Lignin-based carbon dots as high-performance support of Pt single atoms for photocatalytic H2 evolution

Single-atom metal species always run the risk of aggregating into large particles, thus it is essential to develop an appropriate support for Pt single atoms to prevent their aggregation on the premise of ensuring catalytic activity. Herein, N-doped lignin-based carbon dots (NLCDs) prepared by a facile hydrothermal method is used as the support of Pt single atoms for the first time. Through mild photo-assistant method, isolated Pt atoms can bond with the Pyridinic N of NLCDs to form Pt-N-4 coordination structures. Moreover, the enhanced pi -> pi* and n -> pi* electron transitions in Pt-NLCDs make more electrons participate in H-2-evolution. The Pt-NLCDs@CdS ternary photocatalyst shows an exceptional visible-light-driven photocatalytic H-2-evolution (PHE) rate up to similar to 46.10 mmol.h(-1).g(-1). Notably, the ternary system shows ultrahigh photostability in the 60 h continuous photolysis application. Photoelectrochemical analyses demonstrate the synergetic effect of Pt single atoms, NLCDs and CdS will boost the separation, transport and reaction of photogenerated carriers.

Automated summary

In this study, a novel support material, NLCDs, is used to stabilize and disperse Pt single atoms, forming specific coordination structures, which enhances the activity of Pt single atoms in photocatalytic reactions. The ternary system not only exhibits highly active photocatalytic hydrogen evolution performance, but also demonstrates ultrahigh photostability.