Earth-Abundant Bimetallic Catalyst Coated Metallic Nanowire Grown Electrode with Platinum-Like pH-Universal Hydrogen Evolution Activity at High Current Density

A self-supported and flexible current collector solely made of earth-abundant elements; NiCo layered double hydroxide (LDH) wrapped around the Cu nanowires (Cu-W) grown on top of commercially available Cu mesh (Cu-m) outperforms the benchmark 40 wt% Pt/C in catalyzing electrochemical hydrogen evolution reaction (HER). The Cu-m/Cu-W/NiCo-LDH cathode operates both in acidic and alkaline media exhibiting high turnover frequencies (TOF) at 30 mV (0.3 H2 s-1 in 1M KOH and 0.32 H2 s-1 in 0.5M H2SO4, respectively) and minimal overpotentials of 15 ± 6 mV in 1M KOH and 27 ± 2 mV in 0.5M H2SO4 at -10mAcm-2. Cu-m/Cu-W/NiCo-LDH outperforms the activity of 40 wt% Pt/C that needs overpotentials of 22 and 18 mV in 1M KOH and 0.5M H2SO4, respectively. With a tremendous advantage over Pt/C in triggering proton reduction with fast kinetics, similar mass activity and pH-universality, the current collector demonstrates outstanding operational durability at even above -1 Acm-2. The high density of electronic states near the Fermi energy level of Cu-W is found to be the pivotal factor for efficient electron transfer to NiCo-LDH catalyst. This class of self-supported electrode is expected to trigger a rapid progress in developing high performing energy conversion and storage devices.