Controlled growth of a high selectivity interface for seawater electrolysis

• DOI: 10.1073/pnas.2206946119
• Publication Date: 2022-08-29T19:13:40Z
• Authors: Yang Gao; Yurui Xue; Feng He; Yuliang Li
• Keywords: Physical Sciences; 01 natural sciences; 6. Clean water; 0104 chemical sciences

Overall seawater electrolysis is an important direction for the development of hydrogen energy conversion. The key issues include how to achieve high selectivity, activity, and stability in seawater electrolysis reactions. In this report, the heterostructures of graphdiyne-RhOx-graphdiyne (GDY/RhOx/GDY) were constructed by in situ-controlled growth of GDY on RhOxnanocrystals. A double layer interface ofsp-hybridized carbon-oxide-Rhodium (sp-C∼O-Rh) was formed in this system. The microstructures at the interface are composed of active sites ofsp-C∼O-Rh. The obvious electron-withdrawing surface enhances the catalytic activity with orders of magnitude, while the GDY outer of the metal oxides guarantees the stability. The electron-donating and withdrawingsp-C∼O-Rh structures enhance the catalytic activity, achieving high-performance overall seawater electrolysis with very small cell voltages of 1.42 and 1.52 V at large current densities of 10 and 500 mA cm−2at room temperatures and ambient pressures, respectively. The compositional and structural superiority of the GDY-derivedsp-C-metal-oxide active center offers great opportunities to engineer tunable redox properties and catalytic performance for seawater electrolysis and beyond. This is a typical successful example of the rational design of catalytic systems.