Anchoring ultrafine PtNi nanoparticles on N-doped graphene for highly efficient hydrogen evolution reaction
The exploration of high-efficiency electrocatalysts for the hydrogen evolution reaction (HER) is of great significance for sustainable energy conversion applications, yet remain 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 here. The (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 rGO(N) matrix during the chemical reduction process. Benefiting from the bimetallic synergistic effect and strong metal-support interactions, which are expected to accelerate H+ adsorption and H2 desorption, 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 overpotentials of 98 mV at current densities of 10 mA μgPt-1 and an exceptional Tafel slope of 42.7 mV dec-1 for HER, which is exceeding the incumbent commercial Pt/C catalyst. Moreover, the PtNi/rGO(N) also display excellent stability with negligible current degradation continues operation for 5h. The present work would be proposed as an elegant platform toward exploration efficient HER electrocatalysts for various renewable energy conversion applications.