Artificial photosynthesis - Solar fuels
Large scale application of solar light as primary energy source is one of the greatest scientific and technological challenges. The goal is to replace fossil fuels by renewable energy sources and therefore help on the sustainable growth of our society. In the artificial photosynthesis, molecular/nanostructured devices are employed to convert abundant low energetic raw materials (H2O, CO2, resíduos de biomassa) on clean fuels (H2) and valuable chemicals. During the process, a fraction of the solar energy is stored as chemical bonds. That´s why we call them Solar Fuels
At LAFOT-CM, Prof. Antonio Otavio and Osmando carry out investigations on coordination compounds e nanostructured semiconductor oxides for application on artificial photosynthesis. The work involves synthesis, spectroscopic and photoelectrochemical characterization as well as assemble of photoelectrochemical cells (PECs) with hybrid systems. Materials and devices for CO2 reduction, water splitting and biomass valorization are developed.
CO2 reduction
CO2 is a greenhouse gas which accumulation on atmosphere have been pushed by fossil fuel utilization. At the lab, we search for systems able to convert CO2 in chemical species of industrial interest employing solar light
Water splitting
One of the key reactions for clean fuel production is the oxidation of H2O molecules into O2, yileding protons and electrons that can be used for H2 evolution. At LAFOT-CM electrode materials for photoelectrochemical cells (PECs) are developed .
Biomass valorization
One alternative for the water splitting reaction, the biomass photoreforming is an atractive envirionmental and economical solution for H2 production concomitantly with organic species with high added value.
Environmental remediation - Photocatalysis
Advanced oxidation processes
Heterogeneous photocatalysis is a versatile process that can be applied in multiple redox reactions of environmental interest such as in organic polutant oxidation and photoreduction of metal ions. During the process a semiconductor is activated by solar light leading to an electron-hole pair that can further produce high-reactive radicalar species. At LAFOT-CM research is focused on: 1) Development of efficient solar-activated semiconductor systems. 2) Mechanistic investigations of different photocatalytic reactions. This research line is conducted by Professors Antonio Eduardo, Antonio Otavio and Osmando.
Photoactive films
Nanostructured films exhibit simultaneously photocatalytic and superhydrophilic properties and therefore can be used as self-cleaning structures. A surface coated by a photoactive film is able of inhibiting microbial growth and degrade volatile organic contaminants (VOCs) under solar light. Additionally, the surface becomes superhydrophilic, avoiding fogging. The films developed in our lab can be applied in different surfaces (glass, metals, ceramic), in walls and windows exposed to solar radiation. The research team of LAFOT-CM investigates simple and cost-effective methods for thin film deposition such as the layer-by-layer technique, as well as the preparation of nanocomposites (e.g. TiO2/WO3). Check out the animation prepared by our students. Projects on this field are conducted by Prof. Antonio Otavio.
The superhydrophilic properties are evaluated by contact angle measurements:
Registro INPI: BR1020140157751
Coordination compounds
Photoinduced processes
The interaction between light and molecules is a fascinating and inspiring phenomenum. This interaction can lead to photophysical processes, such as luminescence or photochemical ones in which chemical changes occur. The mechanistic understanding of these processes is a core activity in the projects coordinated by Prof. Antonio Otavio T. Patrocinio.
Several metal complexes are investigated, specially those with d6 transition metals such as Ru(II), Re(I) and Ir(III). We employ steady-state and time-resolved spectroscopic techniques to study the photobehavior of the molecular species as funtion of the medium and the coordination environment.
Bioactive complexes
Drugs based on transition metals are indispensable for cancer treatment and other diseases. There is still much more to be understood on the action mechanism of these species, so more effienct active compounds can be engineered with reduced side effects. In this sense, Prof. Gustavo von Poelhsitz and his students develop new potential drugs based on Ru(II) complexes. The new species are fully characterized towards their spectroscopic and redox properties. The interaction with biomolecules and in vitro studies are also carried out aiming at the evaluation of their activity as inhibitors of cancer cells growth. The group has also interest on new drugs for tropical neglected diseases.
Computational simulations
Prof. Antonio Eduardo Machado coordinates theoretical studies for prediction and evaluation of molecular systems on ground and exicited states. Quantum-mechanical methods based on DFT and TD-DFT are typically employed on a myriad of systems.