Efficient and stable La2O3/MoS2 hetero-nanosheet architecture as bifunctional catalysts for seawater electrolysis

Abstract

Seawater electrolysis presents a promising pathway for the sustainable production of hydrogen. Efficient bifunctional catalysts for hydrogen/oxygen evolution reactions (HER/OER) are critical for industrial application of overall seawater splitting. Herein, a nanoflower-like La₂O₃/MoS₂ heteronanosheet bifunctional catalyst is synthesized via a one-step hydrothermal process, which exhibits exceptional bifunctional catalytic activity and durability in both alkaline freshwater and seawater environments. The La₂O₃/MoS₂ exhibits low overpotentials of 106 mV to reach a current density of 10 mA cm⁻² and 360 mV to reach 50 mA cm⁻² in alkaline solution for the HER and OER, respectively. Assembled as an electrolyzer for overall seawater splitting, La₂O₃/MoS₂ as both the anode and cathode deliver a current density of 50 mA·cm⁻²at a quite low cell voltage of 1.89 V. This La₂O₃/MoS₂ architecture is highly advantageous for exposure of active heterointerfaces, accelerate charge transfer and abundant active catalytic sites from the synergistic effect of the heterostructures, achieving dramatically improved performance for OER, HER and overall seawater splitting. Additionally, the catalyst exhibits negligible performance degradation during 120 h of continuous stability testing in seawater. This study introduces a scalable and efficient non-precious metal catalyst, providing a viable solution for high-performance seawater electrolysis and contributing to the advancement of clean hydrogen production technologies.