Low-Pt Amount Supported Polypyrrole/MXene 1D/2D Electrocatalyst for Efficient Hydrogen Evolution Reaction

Developing electrocatalysts with ultralow platinum (Pt) content for hydrogen evolution reaction (HER) is essential. In this work, we electrodeposited Pt nanoparticles on the composite carrier of polypyrrole (PPy) nanowires and MXene materials, thereby obtaining a catalyst with a mixed structure consisting of three materials with different dimensions, namely zero-dimensional (0D) platinum nanoparticles (Pt NPs ), one-dimensional (1D) PPy nanowires and two-dimensional (2D) MXene nanosheets. The PPy nanowires were compounded with MXene nanosheets, which enhanced the conductivity of the catalytic carrier and provided more active sites. The overpotential of the electrocatalyst with ultralow Pt loading (17.11 μg cm ‒2 ) is 40 mV when the current density is 10 mA cm −2 , which is very close to the commercial 20 wt% Pt/C (41 mV). The catalyst exhibits high turnover frequencies (2.21 H 2 s −1 in 0.5 M H 2 SO 4 ) at 100 mV and has relatively good stability due to the composite structural characteristics of 1D and 2D materials. This research provides a direction for the design and development of other MXene-based electrocatalysts and more conductive polymers.