CeO 2 for modulating the electronic structure of nickel-cobalt bimetallic phosphides to promote efficient overall water splitting

• Published in: Journal of colloid and interface science 2024-01, Vol.661, p.690
• Main Authors: Li, Yutong, Yi, Jianhui, Qin, Ruige, Xie, Chenxu, Zhao, Lijun, Lang, Xingyou, Jiang, Qing
• Format: Article
• Language: English
• ISSN: 1095-7103

The discovery of earth-abundant electrocatalysts to replace platinum and iridium for overall water splitting is a crucial step in reducing the cost of green hydrogen production. Transition metal phosphides have drawn wide attention due to their non-toxicity, good chemical stability, low cost, and stable catalytic activity in alkaline electrolytes. We report a three-dimensional flower-like structure composed of core-shell nanoneedles as catalysts, in which CeO is introduced on the surface of nickel cobalt bimetallic phosphide through electrodeposition. And X-ray photoelectron spectroscopy testing and DFT calculations show electron coupling and transfer between CeO and CoP , thereby modulating the electronic structure of the catalyst surface and reducing the adsorption energy of H atoms during the catalytic process, resulting in enhanced catalytic activity. In 1 M KOH, it exhibits a low overpotential of 109 and 296 mV to achieve the current density of 50 mA cm for HER and OER, respectively. When used as both cathode and anode as a bifunctional catalyst, a voltage of only 1.77 V is required to achieve a current density of 50 mA cm , demonstrating great industrial potential.