Nitrogen-doped graphene encapsulated FeCoMoS nanoparticles as advanced trifunctional catalyst for water splitting devices and zinc–air batteries

Abstract Emerging demands for the highly active, durable, and cost-effective trifunctional catalysts for overall water splitting and metal–air batteries in the scientific community. Herein, a novel strategy is demonstrated for the rational design of hierarchical iron cobalt molybdenum sulfide nanoflower encapsulated in nitrogen doped graphene (FeCoMoS@NG) through a facile, cost-effective, and single-step in-situ hydrothermal process. Owing to its hierarchical nanostructures, larger specific surface area, and exclusive porous networks, the optimal FeCoMoS@NG shows excellent catalytic activities for OER ƞ10 = 238 mV, HER ƞ10 = 137 mV, and ORR (0.83 V vs RHE). Most significantly, FeCoMoS@NG||FeCoMoS@NG water splitting device achieves a cell voltage of 1.58 V at 10 mA cm−2. Furthermore, FeCoMoS@NG based zinc–air battery endows a high power density of 118 mW cm−2, and overall water splitting was successfully driven by FeCoMoS@NG based zinc–air battery. This work provides new pathway for designing highly active and durable multifunctional catalysts for energy conversion and storage applications.