Researchers are racing to use the power of the Sun to produce high quantities of electrons that could power appliances; now researchers may be one step closer to accomplishing this.
Devices such as silicon photovoltaic panels, dye-sensitized solar cells, concentrated cells and thermodynamic solar plants all strive to reach this goal, Ecole Polytechnique Fédérale de Lausanne reported.
Researchers at the Ecole Polytechnique Fédérale de Lausanne developed methods for generating fuels such as hydrogen through a process called solar water splitting. They accomplished this using photoelectrochemical cells that split water into hydrogen and oxygen when exposed to sunlight or cluster electricity-generating cells by employing an electrolyzer that separates them.
The new device converts 12.3 percent of the energy diffused by the Sun into hydrogen using the compound perovskite absorbers.
"Both the perovskite used in the cells and the nickel and iron catalysts making up the electrodes require resources that are abundant on Earth and that are also cheap," post-doctoral student Jingshan Luo said. "However, our electrodes work just as well as the expensive platinum-based models customarily used."
This type of conversion makes hydrogen storage possible, helping to overcome one of the largest challenges faced by the renewable electricity industry.
"Once you have hydrogen, you store it in a bottle and you can do with it whatever you want to, whenever you want it," said study leader Michael Grätzel.
Perovskite cells are what make this innovation so efficient and unique; the cells are able to generate an open circuit circulation greater than one volt.
"A voltage of 1.7 V or more is required for water electrolysis to occur and to obtain exploitable gases," Luo said. "This is the first time we have been able to get hydrogen through electrolysis with only two cells!"
The profusion of tiny bubbles escaping the electrodes when the cells are exposed to light give hope of a new way of producing energy in the (possibly) near future.
The findings were published Sept. 25 in the journal Science.
