The concept of photosynthesis was understood when the growth of Plants were studied. It is natural process in which sunlight is used to prepare the required nutrient for the plant with the help of The green pigment of plants ,i.e, chlorophyll. However, when the sun sets there is no way that plant can prepare their meal. SO, artificial photosynthesis came into process which emphasizes on receiving most of the energy from the sunlight and meant to effectively accumulate this energy as to utilize in the required duration.
The energy from the sunlight will be transformed into the chemical energy due to which it becomes more suitable for its storage. In this conversion side products are not produced like the greenhouse gases. On the contrary, in the process carbon dioxide can be utilized in the same way as it does in plants.Plants for this use chlorophyll . It is contained in leaves and captures sunlight, and a set of enzymes and other proteins uses this light to split water molecules into hydrogen, electrons and oxygen (protons).
Electrons and hydrogen are used to convert CO2 into nutrients for the plant, and oxygen is released into the atmosphere.To recreate photosynthesis in artificial conditions, two key steps are necessary: the ability to collect solar energy , and the ability to split water molecules .But unlike natural photosynthesis, it is necessary that the output is not oxygen, but hydrogen (or other biogas, for example, methane).An artificial sheet is the very place where semiconductors and living bacteria are placed, on which sunlight shines. To start the process of artificial photosynthesis in an artificial leaf during that very first experiment, scientists placed all the materials in the water, where carbon dioxide was pumped, while illuminating this entire system with sunlight. Semiconductors in this process collect solar energy, generating the charge necessary for the reaction in this solution to take place. The bacterium uses electrons generated by a semiconductor to convert (or reduce) the molecules of carbon dioxide, and as a result create a liquid fuel – it can be hydrogen, methane, ethanol, etc. At the same time, water is oxidized on the surface of another semiconductor and oxygen is released.
But splitting the water molecule is not so simple, it requires about two and a half electron volts of energy. Therefore, we need a catalyst that “pushes” the chemical reaction.