Photosynthesis is the process by which life on Earth has existed for 2.3 billion years. It allows plants and other organisms to convert sunlight, water, and carbon dioxide into oxygen and energy. But what if we want to live outside the Earth?
According to a new paper published in Nature Communications, artificial photosynthesis could be the key to surviving and thriving away from our planet. There are already ways to produce oxygen by recycling carbon dioxide, but they are unreliable and difficult to maintain. The search for alternative systems continues.
One possibility is to use artificial photosynthesis – collecting solar energy and using it to produce oxygen and recycle carbon dioxide in one device. The only other energy source in such a device would be water. This could reduce the weight and volume of the system, two key criteria for space exploration.
Instead of chlorophyll, which is responsible for light absorption by plants and algae, these devices use semiconductor materials that can be directly coated with simple metal catalysts that support the desired chemical reaction.
Analysis shows that these devices would indeed be viable in addition to existing life support technologies, such as the oxygen generator used on the ISS. This is especially relevant when combined with devices that concentrate solar energy to drive reactions.
There are other approaches as well. For example, it is possible to produce oxygen directly from lunar soil (regolith), but this requires high temperatures. On the other hand, artificial photosynthesis devices could operate at room temperature and pressure typical of Mars and the Moon. This means that they could be used directly in habitats, using water as the main resource.
This is especially interesting given the presumed presence of icy water in the Shackleton lunar crater, which is the intended landing site for future lunar missions. On Mars, the atmosphere is composed of almost 96% carbon dioxide, which is ideal for an artificial photosynthesis device. The intensity of light on the Red Planet is weaker than on Earth because of its greater distance from the Sun, but these devices could work there as well.
Artificial photosynthesis is not only a possibility of survival in space, but also a new way to solve the problem of climate change on Earth. Scientists around the world are working on more efficient artificial photosynthesis devices that can be used to clean the atmosphere of carbon dioxide and produce clean energy.