The key objective of the study was to obtain a cheaper alternative to platinum group metals, which are used as electrodes in electrolyzers for splitting water into oxygen and hydrogen via renewable energy sources. Zinc oxide (ZnO), which is widely used in photocatalytic devices, was chosen as the base material. ZnO particles alone are insufficient to ensure the transfer of electrons required to split a water molecule. However, ZnO can be modified and transformed into nanostructures that have good semiconductor and optoelectronic properties.
The scientists synthesized nanocomposite materials from tungsten disulfide and zinc oxide (WS2–ZnO). “WS2–ZnO nanostructures were synthesized through spark erosion of zinc granules in aqueous solutions of hydrogen peroxide with the simultaneous addition of nanostructured WS2 powder to the reaction zone. This method had never been used before to manufacture WS2–ZnO nanoheterostructures,” Damir Valiev, associate professor at the School of Advanced Manufacturing Technologies, is quoted as saying by Tomsk Polytechnic University.
The authors applied the resulting material to the electrode of a photoelectrochemical cell, after which they irradiated the cell using a stream of light from a xenon lamp that imitated natural sunlight. This experiment was meant to examine the role of the working electrode coated with WS2–ZnO in the photocurrent of the photoelectrochemical cell. The reaction resulted in the release of gaseous hydrogen on the counter electrode and oxygen on the working electrode.
“Our research shows that the obtained WS2–ZnO nanostructures have great potential for use as a photoanode material for photoelectrochemical water splitting to produce hydrogen,” Mr. Valiev is quoted as saying by Tomsk Polytechnic University.
