At Stanford, improved a cheap method of electrolysis of water

In August last year, scientists from Stanford University for the first time demonstrated an inexpensive method of electrolysis of water, that is, the separation of H ₂ O into oxygen and hydrogen. A simple AAA battery is enough to initiate a chemical process. Of course, instead of the battery, you can use a small solar panel, which provides a potential difference of at least 1.5 volts.

Last year, scientists used cathodes and anodes made of nickel and nickel oxide. This is the first experience in the world when electrolysis succeeded in abandoning electrodes made of precious metals (platinum, iridium) and when the process was carried out at such a low voltage.

Now they have managed to reduce the cost and simplify electrolysis, which will make hydrogen fuel even cheaper if the technology is brought to an industrial level. The improved process technology uses the same NiFeO _x catalyst for the cathode and anode . That is, the anode and cathode no longer require a different pH (one acid, the other alkaline), so that they can easily and conveniently be placed in a common vessel with water. It remains only to collect the released oxygen and hydrogen (although oxygen is better not to collect, but immediately released into the atmosphere).

The video below shows how electrolysis from an AAA battery works. Oxygen is released from one electrode, and hydrogen from the other. The authors of the scientific work claim that the reaction intensity is even higher than with a combination of electrodes made from traditional iridium oxide and platinum.

The reaction is stable and very active on the entire surface of the electrodes.



The secret of the trick is in the structure of the NiFeO _x catalyst . Although these are simple materials, the structure of the material is very specific. It is somehow "grown" on carbon nanofibers (from scientific work it is not entirely clear how to make it). Scientists say that this wonderful catalyst in the future can be adapted for other chemical reactions, in addition to electrolysis of water.

Although such a technology looks rather implausible, and all eight co-authors of the scientific work are Chinese, we should not forget that they work in the department of materials science and technology at Stanford University, one of the most respected scientific institutions in the world.

As a result of a catalytic reaction, metal oxide nanoparticles (iron, cobalt, nickel oxides or mixtures of their oxides) of about 20 nm in size are electrochemically converted to ultrafine NiFeO _x nanoparticles with a diameter of 2-5 nm as a result of a lithium-induced reaction. Unlike traditional chemical synthesis, the inventors note, this method allows you to maintain an excellent electrical connection between the nanoparticles and leads to the formation of large areas for the catalytic reaction.

During the experiment, the continuous operation of the device in this way for a whole week (more than 200 hours) without electrode degradation was checked, saysAnd Cui (Yi Cui), one of the authors of scientific work. He added that the efficiency of water electrolysis is 82% at room temperature (apparently, at normal pressure, too).

The results of the study were published on June 23, 2015 in the journal Nature Communications (in free access).

As already noted a year earlier, this is a very important project, because it greatly simplifies the technology of manufacturing fuel cells with hydrogen. On such cells can work both mobile electronics and cars.


Toyota Mirai, one of the world's first hydrogen fuel cell vehicles. Sales began on December 15, 2014. Under the bottom, he has two cylinders of hydrogen under a pressure of 70 MPa. Refueling takes 3-5 minutes. Range: 480 km

It is important that during the combustion of hydrogen, the only by-product of combustion is water. The same water, which was split into components, for example, by sunlight at the first stage of the technical process.