Photocatalysts, which accelerate chemical reactions and are activated by light, can be used in the production of hydrogen, the processing of carbon dioxide and the purification of water from synthetic substances. However, their commercial use is hampered by the high cost of platinum, one of the chief types of catalytic raw materials, whereas cheap alternatives are rather ineffective: they mainly absorb ultraviolet light, which makes up only a few percent of the solar spectrum.
Chemists from the Institute of Physical Chemistry and Electrochemistry RAS have attempted to solve this problem by creating photocatalysts based on graphene oxide and placing them in an external electric field. Graphene oxide – a widely available nanocompound of carbon, hydrogen and oxygen – is usually able to perceive an electric field, but is not sensitive to light. The authors of the study made graphene oxide sensitive to light by adding organic dyes to the oxide. This photocatalyst was able to accelerate the transfer of electrons in the presence of an external electric field.
To test this, the authors placed the photocatalyst in an aqueous solution containing a pollutant; under the influence of an external electric field, its decomposition accelerated twofold.
“The photocatalytic cell with a contactless external field source that we used is an accessible, cheap and eco-friendly technology. Our technology is about photocatalysis in capacitors, and capacitors can be charged from sunlight, among other things, and do not require the cell to be permanently connected to the grid. One can easily imagine that it can be modified to use electric fields from high-voltage power lines to operate water purification systems or chemical synthesis modules,” Maria Kalinina, doctor of chemical sciences, is quoted as saying by the Russian Science Foundation.
