Boosting activity and stability by coupling Pt–Ni nanoparticles with La-modified flexible carbon nanofibers for hydrogen evolution reaction

Abstract

Platinum (Pt) is considered as the most efficient catalyst for hydrogen evolution reaction (HER) with a nearly zero overpotential, but it is limited by the high cost and poor stability. Herein, we report an efficient electrocatalyst of Pt–Ni alloy nanoparticles (NPs) supported on the La-modified flexible carbon nanocomposite fibers (PtNi@La-CNFs) for HER. The rare earth metal oxide in the catalyst has a structure-effect relationship with the carbon fibers to form a flexible fiber membrane. Experimental results show that the macroscopic and microscopic properties of carbon nanocomposite fibers can be optimized by doping La2O3, and the Pt–Ni NPs can be anchored effectively. The Pt1Ni1@La-CNFs electrocatalyst exhibits a small overpotential of 32 mV to achieve current density of 10 mA cm−2 with a low Tafel slope of 51 mV dec−1 in alkaline medium, outperforming that of Pt@La-CNFs and the commercial Pt/C catalyst. This study reveals that the multiple coupling effect of rare earth compound, precious metal, and transition metal in composite catalyst can tailor its the electronic configuration, and results in an enhanced HER performance. This work opens up a novel approach to design high active and low cost Pt-based HER catalysts.