Korean researchers design electrode to produce green hydrogen from electrolysis

In South Korea, electrochemical catalysts used in water splitting often show poor performance due to low electrical conductance of (oxy)hydroxide species produced in situ. To overcome this challenge, researchers from Gwangju Institute of Science and Technology in Korea have now designed an electrode with Schottky Junction formed at the interface of metallic Ni-W5N4 and semiconducting NiFeOOH. The proposed electrode shows excellent catalytic activity and can facilitate industrial seawater splitting continuously for 10 days.

Green hydrogen (or H2) produced from renewable energy resources is the fuel of a decarbonized future. Electrolysis or splitting of water into oxygen and hydrogen with the help of an electrochemical cell is one of the most popular ways of producing green H2. It is a simple reaction, ensures high-quality products, and has zero carbon emissions. Despite its advantages, however, electrochemical water splitting is yet to gain prominence on a commercial scale. This is because of the low electrical conductivity of active (oxy)hydroxide catalysts generated in situ during the electrochemical processes. This, in turn, leads to restricted catalytic activity, hampering hydrogen as well as oxygen evolution reactions in the cell.

The problem of (oxy)hydroxide’s poor electrical properties has been a long-standing challenge towards the achievement of efficient water splitting. Now, a team of researchers led by Associate Professor Junhyeok Seo from the Department of Chemistry at Gwangju Institute of Science and Technology, have found a solution to this issue in the form of Schottky junctions.

In a recent study made available online on 30 August 2023 and to be published in Volume 340 of the Applied Catalysis B: Environmental journal in January 2024, they demonstrated an electrode with Schottky junction formed at the interface of metallic nickel-tungsten nitride (Ni-W5N4) and semiconducting n-type nickel-iron (oxy)hydroxide (NiFeOOH) catalyst. This electrode was able to overcome the conductance limit of (oxy)hydroxide and improved the water splitting ability of the setup.