Ultra-fast preparing carbon nanotube-supported trimetallic Ni, Ru, Fe heterostructures as robust bifunctional electrocatalysts for overall water splitting

Abstract Rapid preparing unique carbon-based carriers via simple, low-cost and eco-friendly synthetic strategies benefits for the design of efficient catalysts and their commercial application. In this work, the Fe/C@CNT carrier that the carbon-coated Fe/Fe3C nanoparticles (iron-carbon heterostructure) uniformly growing on carbon nanotube (CNT) is obtained via the fast pyrolysis (only 3 min) of ferrocene on CNT with efficient microwave thermal effect. The unique heterostructure improves the dispersity and stability of Ni, Ru-based compounds on Fe/C@CNT carrier during the fast preparation progress of Ni-Ru@Fe/C@CNT catalyst and the subsequent catalytic reaction processes, and promotes the formation of efficient active sites for HER (Ru (0)) and OER (Ni (3 + )). Therefore, Ni-Ru@Fe/C@CNT shows robust bifunctional activity and enduring stability, and just needs the low overpotential about 32 mV and 246 mV to reach the current density of 10 mA cm−2 for HER and OER, respectively, which are better than the Ni-Ru-Fe@CNT using smooth CNT as carrier and even far superior to the commercial Pt/C and RuO2. More importantly, the whole preparation process of Ni-Ru@Fe/C@CNT is fast, simple and low-cost, providing a facile and environment friendly strategy to rapidly prepare efficient catalysts.