The Edge Effects Boosting Hydrogen Evolution Performance of Platinum/Transition Bimetallic Phosphide Hybrid Electrocatalysts

Platinum (Pt) is regarded as a promising electrocatalyst for hydrogen evolution reaction (HER). However, its application in an alkaline medium is limited by the activation energy of water dissociation, diffusion of H+, and desorption of H*. Moreover, the formation of effective structures with a low Pt usage amount is still a challenge. Herein, guided by the simulation discovery that the edge effect can boost local electric field (LEF) of the electrocatalysts for faster proton diffusion, platinum nanocrystals on the edge of transition metal phosphide nanosheets are fabricated. The unique heterostructure with ultralow Pt amount delivered an outstanding HER performance in an alkaline medium with a small overpotential of 44.5 mV and excellent stability for 80 h at the current density of -10 mA cm(-2). The mass activity of as-prepared electrocatalyst is 2.77 A mg(Pt)(-1), which is 15 times higher than that of commercial Pt/C electrocatalysts (0.18 A mg(Pt)(-1)). The density function theory calculation revealed the efficient water dissociation, fast adsorption, and desorption of protons with hybrid structure. The study provides an innovative strategy to design unique nanostructures for boosting HER performances via achieving both synergistic effects from hybrid components and enhanced LEF from the structural edge effect.

Automated summary

This study fabricates unique heterostructures by depositing platinum nanocrystals on the edge of transition metal phosphide nanosheets, showing outstanding HER performance in an alkaline medium. The heterostructures exhibit low platinum usage amount and excellent stability. Additionally, the study provides a new strategy for designing enhanced HER performance.