Prof. Avner Rothschild (Head), Prof. Yaron Paz, Prof. Gadi Schuster,
Prof. Noam Adir, Dr. Lilac Amirav, Dr. Galia Maayan, Dr. Maytal Caspary Toroker
Ben Gurion University:
Dr. Maya Bar-Sadan, Prof. Ira Weinstock, Dr. Avi Niv
Prof. Ronny Neumann
Dr. Dror Noy
The group is researching the efficient and cost-effective direct conversion of solar energy into H2, CO and O2 through photoelectrolytic and photocatalytic water splitting and CO2 reduction. The products – H2, CO and O2 – will be used to produce liquid fuels.
The development of methods for storing solar energy in high-energy chemical products is crucial for the large-scale deployment of solar energy and this is considered one of the greatest scientific and technological challenges of this century.
Using water and CO2 as feedstock chemicals, this process has proven its applicability in sustaining life on earth for more than 2.5 billion years through oxygenic photosynthesis. However, natural photosynthesis far less efficient than man-made photovoltaic or solar-thermal technologies, and the end products - sugars and other types of biomass - are unsuitable for direct industrial application, requiring thermochemical, catalytic or biochemical processing to convert them to useful fuel.
This group is investigating an alternative route for the production of solar fuels by means of direct water splitting into H2 and O2, CO2 splitting into CO and O2, and reduction of CO2 with water yielding CO or methanol. H2 is an essential ingredient in the production of liquid fuels, either by reaction with CO2 or in the various hydro-treating processes of oils.
Similarly, CO can also be reacted further with H2O to produce H2 via the water-gas shift reaction. O2 produced in these processes can be used for oxy-gasification of the biomass to produce H2 and CO that will be further converted into liquid fuels.
Construction of an effective system requires the development of the appropriate catalytic components for the anodic (water oxidation) and cathodic (CO2 or proton reduction) reactions, as well as their integration and coupling with an efficient solar energy harvesting system that will provide the necessary driving force for the process.
This group is developing efficient and cost-effective technologies for solar-induced water splitting and CO2 reduction.
The products – H2, CO and O2 – will be used to produce liquid fuels. Considering the low efficiency and high cost of state-of-the-art technologies for solar-induced water splitting and CO2 reduction, it is clear that innovative approaches are necessary to overcome the complex difficulties involved. The group addresses this challenge by carrying out basic and applied multidisciplinary research in chemistry, biology, physics and materials science that will lead to the rational design of complex systems that combine semiconductor photoelectrodes together with inorganic, organic and biological photocatalysts. The synergy between different photosystems will be used to overcome the intrinsic limitations of individual components and achieve efficient conversion of solar energy to fuels. Towards this end, the research aims to achieve the following specific objectives:
(1) The development of stable photoelectrodes for water splitting
(2) The development of organic and inorganic synthetic catalysts for water oxidation and reduction
(3) The development of biological photocatalysts for water oxidation suitable for coupling with electrode materials and synthetic nano-catalysts
(4) The Integration of water oxidation and reduction photocatalysts with semiconductor photoelectrodes into multicomponent systems for efficient water splitting
(5) The development of organic, inorganic and hybrid catalysts for overall water splitting
(6) The development of organic, inorganic and hybrid catalysts for the reduction of CO2 with water
(7) The development of tunable antennae for light harvesting and energy coupling, via plasmonic modes, to drive photochemical reactions
(8) The scale-up of complete systems for water splitting and CO2 reduction and test them in the field.
This research will enable rational design of efficient and cost-effective systems for solar-induced water splitting and CO2 reduction that meets the following targets:
(1) Stable photo electrodes modified with organic or inorganic catalysts that achieve water-splitting photocurrent densities of 8 mA/cm2 (or higher) at the reversible water oxidation and reduction potentials; this corresponds to photo electrolysis efficiency of 10% (or higher)
(2) Water splitting tandem cells achieving solar to hydrogen conversion efficiency of 5% (or higher)
(3) Photoelectrolytic cells based on biological photocatalysts achieving solar to hydrogen conversion efficiency of 1% (or higher)
(4) Photocatalytic splitting of CO2 to CO and O2 and photoreduction of CO2 with H2O under visible light with a quantum efficiency of 5% using abundant transition metal based compounds
(5) Nano-textured antennae for light harvesting in different spectral ranges that couple photon energy to surface plasmons and transfer the energy to drive water oxidation and CO2 reduction reactions.