A nickel-based dendritic electrode matrix with high surface efficiency mass transfer for highly efficient overall water splitting

Abstract

Electrodes are key components in water splitting. Owing to their porous structures, commercial foam metal electrode matrices can provide numerous active sites. However, the complex and disordered surface structure impedes the release of the generated gas bubbles, and sluggish mass transfer usually becomes a bottleneck in the electrochemical reaction kinetics. For this purpose, this study proposes a pulse-jet electrodeposition method for the preparation of nickel-based dendritic electrode matrices (NDEM). This research shows that the electrode matrix prepared under the conditions of V = 26 V, PW = 10 μs, and PI = 35 μs has a unique surface structure, which can quickly release bubbles, effectively attract ions, and accelerate mass transfer on the electrode surface, resulting in excellent electrochemical performance. After loading the catalyst, the NDEM requires only 1.552 V to reach a current density of 10 mA cm−2. At an electrolysis voltage of 2.5 V, the hydrogen production was 45% higher than that of the NF electrode, and it had excellent stability. This study opens a new avenue for the design of highly efficient and low-cost electrodes for water splitting.