Anchoring ultrafine PtNi nanoparticles on N-doped graphene for highly efficient hydrogen evolution reaction

Abstract

The exploration of high-efficiency electrocatalysts for the hydrogen evolution reaction (HER) is of great significance for sustainable energy conversion applications, yet it remains a grand challenge. Herein, a facile and rapid strategy to synthesize ultrafine PtNi nanoparticles (NPs) anchored on N-doped graphene (rGO(N)) (labeled as PtNi/rGO(N)) at room temperature is demonstrated. (3-Aminopropyl) triethoxysilane (APTES) is selected as an effective nitrogen source to form two kinds of nitrogen (doping N and amine N) simultaneously for fabricating a rGO(N) matrix during the chemical reduction process. Benefiting from the bimetallic synergistic effect and strong metal–support interactions, this composite is expected to accelerate H⁺ adsorption and H₂ desorption and reduce the transport resistance of electrons and hydrogen intermediates. As a consequence, the PtNi/rGO(N) with ultralow Pt loading amount (1.2 μg per electrode area (cm²)) exhibits extraordinary catalytic activity with a small overpotential of 98 mV at a current density of 10 mA μg_Pt⁻¹ and an exceptional Tafel slope of 42.7 mV dec⁻¹ for HER, exceeding the incumbent commercial Pt/C catalyst. Moreover, the PtNi/rGO(N) also displays excellent stability with negligible current degradation during a continuous operation for 20 h. The present work would be proposed as an elegant platform toward the exploration of efficient HER electrocatalysts for various renewable energy conversion applications.