Clean energy through artificial photosynthesis: the PHOEBUS project gets into full swing
Producing clean chemical energy and storing it efficiently by mimicking the natural process of plant photosynthesis. This is the objective of PHOEBUS (PHOto-induced Energy flow in Bio-inspired molecular circuits probed with Ultrafast two-dimensional electronic Spectroscopy), the research project coordinated by the Polytechnic University of Milan and funded by the European Commission with a grant awarded to Margherita Maiuri under the Marie Skłodowska-Curie Global Fellowships - MSCA-GF. After two years of research carried out at the Princeton University’s Chemistry Department laboratories in the United States, for the next two years the study will be conducted at the Polytechnic University of Milan under the coordination of Giulio Cerullo.
The project aims to investigate the molecular mechanisms related to plant photosynthesis in order to produce artificial molecular circuits able to mimic this clever natural mechanism of energy production. The absorption of light by the molecules contained in the photosynthetic organisms, for example, occurs within fractions of seconds. The initial photo-excitation caused by sunlight is instantly dispersed on all photo-excited molecules and is transmitted to the “power station” of the photosynthetic organism through a pigment chain.
To achieve these results, PHOEBUS has photographed these mechanisms through sophisticated instruments that allowed generating flashes of light of an infinitesimal duration. The techniques for the generation and development of femtosecond laser sources (1 femtosecond, or a millionth of a billionth of a second), available at the laboratories of the Physics Department at the Polytechnic University of Milan, allowed the researchers to observe in real time the initial time instants that follow solar excitement in elementary bacterial organisms.
After two years of research, the PHOEBUS project has demonstrated that energy transport in natural systems is governed by the laws of quantum mechanics, through a sophisticated molecular architecture that directs solar energy in an extremely efficient way towards the molecular power station, where it is used to convert carbon dioxide into sugars, which serve as “fuel” for molecules.
PHOEBUS has studied complex natural organisms, such as algae, and new artificial systems, never synthesized before. In these artificial systems, photo-active molecules are linked together through chemical bonds to mimic the pigment structure in photosynthetic proteins and thus reproduce the effects of the photosynthesis process in the laboratory. The end goal is the production of an “artificial leaf” that converts water into fuels such as hydrogen and oxygen and, at the same time, cleans the atmosphere, thus reducing the concentration of carbon dioxide.