Engineering Cu/NiCu LDH Heterostructure Nanosheet Arrays for Highly-Efficient Water Oxidation

Abstract

The development of stable and efficient electrocatalysts for oxygen evolution reaction is of great significance for electro-catalytic water splitting. Bimetallic layered double hydroxides (LDHs) are promising OER catalysts, in which NiCu LDH has excellent stability compared with the most robust NiFe LDH, but the OER activity is not satisfactory. Here, we designed a NiCu LDH heterostructure electrocatalyst (Cu/NiCu LDH) modified by Cu nanoparticles which has excellent activity and stability. The Cu/NiCu LDH electrocatalyst only needs a low over-potential of 206 mV and a low Tafel slope of 86.9 mV dec−1 at a current density of 10 mA cm−2 and maintains for 70 h at a high current density of 100 mA cm–2 in 1M KOH. X-ray photoelectron spectroscopy (XPS) showed that there was a strong electronic interaction between Cu nanoparticles and NiCu LDH. Density functional theory (DFT) calculations show that the electronic coupling between Cu nanoparticles and NiCu LDH can effectively improve the intrinsic OER activity by optimizing the conductivity and the adsorption energy of oxygen-containing intermediates.

Prominent development of Ni-based oxygen-evolving electrocatalysts for water splitting

“…113 Accordingly, the introduction of Cu in Ni-based electrocatalysts is expected to enhance the charge transport process, resulting in an increase in their OER performances. Different types of NiCu OER catalysts have been reported including NiCu alloys, 114–116 NiCu LDH, 117 NiCu mixed oxide, 118 and NiCu sulfide. 119…”

Fabrication of Al-Ni Alloys for Fast Hydrogen Production from Hydrolysis in Alkaline Water

“…Therefore, developing environmentally friendly hydrogen production methods is crucial for its use as clean energy. Hydrolysis of chemical hydride [4][5][6][7][8][9][10][11], active metals [12][13][14][15][16][17][18][19][20][21], and electrolysis [22][23][24][25][26][27][28][29] methods have been studied as environmentally clean hydrogen production methods. Among them, the on-board hydrogen production via the hydrolysis of electrochemically active metals, like Al [14,[17][18][19][20][21] and Mg [12,13], has gained significant attention as it eliminates the necessity for hydrogen storage.…”