CeO<sub>2</sub> Nanoparticles Anchored in Cation-Vacancies NiFe-LDH toward Efficient Oxygen Evolution Reactions in Green Sustainable Seawater Electrolysis
Zhaokun Wang, Liyan Wang, Liang Chu, Mu Yang, Ge Wang
Abstract
In recent decades, there has been significant interest in eco-friendly hydrogen production from seawater electrolysis. However, the corrosive nature of Cl – on metal substrates prevents Ni–Fe layered hydroxides (NiFe-LDH) from being catalysts for direct use in seawater electrolysis. In this study, a NiFe-LDH attached to copper nanowire arrays with synergistic decoration of cerium dioxide (CeO 2 ) nanoparticles and cationic defects was synthesized. It requires only 208 and 230 mV overpotentials under 1 M KOH and alkali wild seawater for 100 mA·cm –2 . Moreover, the catalyst is capable of functioning at 400 mA·cm –2 in alkali natural seawater, with a retention rate of 99% for 80 h. Results of theoretical and experimental analyses indicate that the Ce–O–Ni unit formed by cation defects anchoring CeO 2 particles promotes the charge transfer of NiFe-LDH to CeO 2, which greatly reduces the adsorption energy of the OER active intermediates. The hard and soft acid-based (HSAB) theory states that the selective binding of OH – by high-valence Ni is responsible for the improvement in seawater stability and selectivity. This research aims to outline key considerations in developing high-efficiency seawater electrolysis catalysts.