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

• Published in: Materials Vol. 16; no. 9; p. 3372
• Main Authors: Wang, Ao-Bing, Zhang, Xin, Xu, Hui-Juan, Gao, Li-Jun, Li, Li, Cao, Rui, Hao, Qiu-Yan
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.04.2023; MDPI
• Subjects: Adsorption; Bimetals; Cu/NiCu LDH; Current density; Density functional theory; Density functionals; Electric properties; Electrocatalysts; Electrodes; Energy consumption; heterostructure; Heterostructures; Hydrogen; Hydroxides; Iron compounds; Nanomaterials; Nanoparticles; Nanosheets; Nickel; Nickel compounds; Oxidation; Oxygen evolution reactions; Photoelectrons; Specific gravity; Spectrum analysis; Stability; Voltammetry; water oxidation; Water splitting; X ray photoelectron spectroscopy; X-ray spectroscopy; Cu/NiCu LDH; water oxidation; heterostructure; density functional theory
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16093372

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 at a current density of 10 mA cm and maintains for 70 h at a high current density of 100 mA cm 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.