Carbon dots regulate the interface electron transfer and catalytic kinetics of Pt-based alloys catalyst for highly efficient hydrogen oxidation

Abstract The regulation of interface electron-transfer and catalytic kinetics is very important to design the efficient electrocatalyst for alkaline hydrogen oxidation reaction (HOR). Here, we show the Pt-Ni alloy nanoparticles (PtNi2) have an enhanced HOR activity compared with single component Pt catalyst. While, the interface electron-transfer kinetics of PtNi2 catalyst exhibits a very wide electron-transfer speed distribution. When combined with carbon dots (CDs), the interface charge transfer of PtNi2-CDs composite is optimized, and then the PtNi2-5 mg CDs exhibits about 2.67 times and 4.04 times higher mass and specific activity in 0.1 M KOH than that of 20% commercial Pt/C. In this system, CDs also contribute to trapping H+ and H2O generated during HOR, tuning hydrogen binding energy (HBE), and regulating interface electron transfer. This work provides a deep understanding of the interface catalytic kinetics of Pt-based alloys towards highly efficient HOR catalysts design.