Access to clean water and increased use of renewable energy sources are considered to be two of the main goals in the effort to achieve a sustainable living environment. In this frame, the use of solar light to purify drinking water and to obtain a clean fuel such as hydrogen are very appealing technologies. For both cases, there is the possibility of using the process known as photocatalysis, which makes use of solids (photocatalysts) that can absorb light and in this way be activated to run chemical reactions. The most used and studied photocatalyst is titanium dioxide (TiO2), because it shows a unique combination of properties, including efficiency, low cost and non-toxicity, that has not been matched by any other material to date. However, titanium dioxide presents one major drawback that limits its efficiency: it is able to absorb only UVA light, which accounts for, approximately, 5 % of the solar light reaching the Earth crust. Therefore, a large effort is being put by the researchers in this topic into the development of photocatalysts that can make use of a larger extent of the solar spectrum. One of the possible strategies to reach this goal is to combine TiO2 with another solid that can absorb visible light, present in solar light in a much greater extent than UVA, obtaining a composite material that exploits the advantages of both components: the reactivity of TiO2 and the visible light absorption of the second constituent. For this to happen, of course, it is necessary to rationally design the composite so that its components can interact to the greatest possible extent.
IMDEA Energy has recently taken part in a review article* led by the University of Zagreb (Croatia), and together with the University of Ljubljana (Slovenia) and the University of Cincinnati (Ohio, USA), which describes the most recent developments in the field of photocatalysis for water purification and hydrogen production using this kind of composite materials, and which is framed in a special issue devoted to this technology in the open-acess journal Materials, of which Hrvoje Kušić and Ana Loncaric Bozic (Univ. Zagreb), together with Fernando Fresno (IMDEA Energy) are guest editors.
(*) Perović, K., de la Rosa, F.M., Kovačić, M., Kušić, H., Štangar, U.L., Fresno, F., Dionysiou, D.D., Bozic, A.L. Recent achievements in development of TiO2-based composite photocatalytic materials for solar driven water purification and water splitting. Materials, 13 (2020) 1338, http://dx.doi.org/10.3390/ma13061338
More information: Fernando Fresno, Senior Assistant Researcher, Photoactivated Processes Unit. email@example.com
Different action modes of composite materials for photocatalytic pollutant degradation and hydrogen production