In today’s modern age, technology can easily replicate biological processes seen in humans and other complex organisms. Now researchers have developed an artificial leaf, which can mimic photosynthesis, the process used by plants to convert light energy into the biological fuel needed for the organism’s sustenance.
HOW DOES THIS ARTIFICIAL LEAF WORK?
Over the past five years, researchers at Caltech’s Joint Center for Artificial Photosynthesis have been working on developing a “efficient, safe, [and] integrated solar-driven system for splitting water to create hydrogen fuels,” according to LinkedIn. The completed project will not be commercialized anytime soon, but it does represent an important milestone in the push for a clean-energy economy, fueled by renewable energy sources, such as solar power.
Currently, the artificial leaf, discussed in the journal Energy and Environmental Science, can operate for 40 continuous hours and is one square centimeter in area. Due to its small size, however, it is only capable of converting 10 percent of the energy in the sunlight into chemical fuel.
According to Business Standard, the new system utilizes three main components: a membrane and two electrodes – one photoanode and one photocathode.
THE ROLE OF EACH COMPONENT IN THE ARTIFICIAL LEAF
Each component of the artificial leaf serves a specific function in the photosynthetic process:
Photoanode: oxidizes water molecules using sunlight and generates protons, electrons and oxygen gas.
Photocathode: forms hydrogen gas by recombining the protons and electrons.
Membrane: acts as a barrier, separating the oxygen and hydrogen gases to allow hydrogen fuel to be collected and pushed into a pipeline.
Semiconductors (such as silicon or gallium arsenide): used in solar panels to efficiently absorb light. To prevent oxidation or rust, a layer of titanium dioxide (TiO) (found in sunscreens) is added onto the electrodes.
Catalyst: a 2-nanometer-thick layer of nickel is added to the TiO surface, to drive the water-splitting reaction.
The combination of all these components help drive the artificial photosynthetic process. “[The] work shows that it is indeed possible to produce fuels from sunlight safely and efficiently in an integrated system with inexpensive components,” states Lewis, the leader behind the project. “Of course, [they] still have work to do to extend the lifetime of the system and to develop methods for cost-effectively manufacturing full systems, both of which are in progress.”