Scientists in China have showed that artificially corroded stainless steel plates can act as excellent electrocatalysts for splitting water into hydrogen and oxygen.
Their technology, published in Angewandte Chemie, represents a surprisingly simple approach toward addressing a long-standing problem in electrocatalytic water splitting, one of the most promising next-generation technologies for environmentally friendly and inexpensive energy conversion and storage.
Current electrocatalytic water splitting technology relies on metal oxide electrocatalysts, but the sluggishness of the oxidation reaction is responsible for its high costs and low performance. Furthermore, the technology is difficult to implement as an industrial process even though water splitting is the most important energy-converting reaction on Earth.
In an unusual approach, Professor Zhang Xinbo from the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences and colleagues turned a simple stainless steel plate electrode into a highly-efficient electrocatalyst just by artificially corroding its surface, using hydrothermal and electrochemical treatments in alkali solution.
The rusty electrode is ideal for catalysis as the nickel hydroxides released from the steel act as excellent electrocatalysts. The electrode’s rougher and more basic surface makes it perfectly wettable, meaning that it provides excellent contact to the current collector. It is also stable and robust.
Alluding to how rusty metal is normally perceived as trash, the scientists say their method is “turning waste into treasure,” and may represent a promising start to the development of next-generation water splitting technologies. (Asian Scientist)
