Controlled growth of a high selectivity interface for seawater electrolysis.

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-RhO-graphdiyne (GDY/RhO/GDY) were constructed by in situ-controlled growth of GDY on RhO nanocrystals. A double layer interface of -hybridized carbon-oxide-Rhodium (-C∼O-Rh) was formed in this system. The microstructures at the interface are composed of active sites of -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 withdrawing -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 at room temperatures and ambient pressures, respectively. The compositional and structural superiority of the GDY-derived -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.