Reports have suggested that this year atmospheric carbon dioxide reached its highest levels on earth in the last three million years. Scientists claim that solar technologies are the best solution to carbon-neutral renewable energy. This is because there is enough energy in one hour's worth of global sunlight that it can meet all human demands for about a year.
A significant development in the race to develop carbon-neutral renewable energy sources was recently achieved. Researchers have reported that they developed the first fully integrated nanosystem for artificial photosynthesis. The artificial leaf is a popular term for such sort of system. However, the central concept for the success of this project is “artificial forest.” This is a massive advancement in the Artificial Photosynthesis Market as this technology can produce cheap hydrogen compared to other similar technologies present.
Chloroplasts in green plants are responsible for carrying out photosynthesis. Similarly, an artificial photosynthesis system contains an interfacial layer for charge transport, two semiconductor light absorbers, and separated co-catalysts. To facilitate solar water spitting, the tree was synthesized like nanowire heterostructures consisting of titanium oxide branches and silicon trunks. Visually, all these nanostructures combined to give the idea of an artificial forest.
Artificial photosynthesis refers to a process in which solar energy gets converted into chemical fuels and is regarded as a technology that has excellent potential among all solar technologies. However, the hurdle with artificial photosynthesis is that it needs to produce hydrogen that is cheap enough to compete with fossil fuels. To meet this challenge, an integrated system that has the ability to absorb sunlight efficiently is required. This system can then produce charge-carriers to drive separate water reduction and oxidation half-reactions.
The team also took help from Z-scheme in their systems. They deployed two Earth-abundant and stable semiconductors known as titanium oxide and silicon. They were loaded with co-catalysts, and an ohmic contact was inserted between them. The silicon was employed for hydrogen-generating photocathode, while titanium oxide was for oxygen-generating photoanode. The architecture of the system was specially made to be tree-like so that its performance could be maximized. Like real trees in a forest, the dense arrays in the system help suppress the sunlight reflection and facilitate more surface area for fuel production reactions.
Researchers have stated that they have further ideas on developing photoanodes that may have better performance than titanium oxide. And they are quite confident that they will find a substitute for it.