One of the main challenges that humankind is facing nowadays is to obtain a clean and renewable energy source. This is a major concern because it will to help reduce global warming by reducing the CO2 emissions to the atmosphere, and other type of pollution problems such as, nuclear waste. In addition, fossil fuels reserves, which are our main energy source in these days, are decreasing and their extraction is every time more difficult and contaminant. One of the most attractive alternative to fossil fuels is the use of sunlight because with the energy coming from the Sun to Earth in one hour we could obtain the energy to sustain the whole planet for a full year. Sunlight energy has been used since Earth early times in nature by green plants to obtain energy. The process is the so-called photosynthesis through which green plants produce sugar (its own energy) from sunlight, water and carbon monoxide (CO2). In other words, plants are capable of storing sunlight energy in chemical bonds. Solar fuels, or artificial photosynthesis, is the field that aims to mimic green plants to store sunlight energy into the chemical bonds of small molecules (hydrogen, methanol, …) which later on can release the accumulated energy. As in natural photosynthesis a key process is the oxygen production from water, in other words, the electron extraction from water to, later on, reduce CO2. This is a difficult process that needs first a system to capture the sunlight energy, which needs to be transferred to a catalyst to facilitate the reaction. This project was focused on the understanding of all the fundamental processes taking place in different artificial systems (from molecular to materials), from light absorption to oxygen production. With this gained knowledge, the design of new systems will be more efficient and successful.
