Photocatalytic materials are pivotal for the implementation of disruptive clean energy applications like conversion of H2O and CO2 into fuels and chemicals driven by solar energy. However, efficient and cost-effective materials able to catalyze the chemical reactions of interest when exposed to visible light are scarce due to the stringent electronic conditions that they must satisfy. Chemical and nanostructuring approaches are capable of improving the catalytic performance of known photoactive compounds, however the complexity of the synthesized nanomaterials and the sophistication of the employed methods make systematic design of photocatalysts difficult. Here, we present the results of recent first-principles studies on binary oxides and semiconductor materials that have the potential to improve the systematic screening and rational design of photocatalytic materials1,2.
First, we introduce an efficient multi-configurational supercell approach for estimating the mixing thermodynamics and structural and functional properties of semiconductor solid solutions, which takes into consideration the effects of configurational disorder and lattice vibrations on the free energy. The method is applied to (GaP)x(ZnS)1-x solid solutions with the finding that compositions x≈25, 50, and 75% render promising photocatalysts for water splitting under visible light. And second, we show that application of biaxial stress on semiconductor binary oxides can modify their optoelectronic and catalytic properties in a significant and predictable manner. In particular, upon moderate tensile strains CeO2 and TiO2 become suitable materials for photocatalytic conversion of H2O into H2 and of CO2 into CH4 under sunlight, respectively. The band gap shifts induced by biaxial strain are reproduced qualitatively by a simple analytical model that depends only on structural and dielectric susceptibility changes. Thus, compounds mixing and strain engineering represent two promising routes for methodical screening and rational design of photocatalytic materials.
- Shenoy, J., N., Hart, J., N., Grau-Crespo, R., Allan, N. L. & Cazorla, C. Mixing thermodynamics and photocatalytic properties of GaP-ZnS solid solutions. Advanced Theory and Simulations, 2, 1800146 (2019).
- Liu, Z., Shenoy, J. N., Menendez, C., Hart, J. N., Sorrel, C. C. & Cazorla, C. Strain engineering of binary oxides for photocatalytic applications. Nano Energy 72, 104732 (2020).
Dr. Cazorla was awarded his doctorate in Computational Physics by the Polytechnic University of Catalonia (Barcelona, Spain) in 2006. From 2006 to 2010, Dr. Cazorla worked as a postdoctoral researcher in the group of Prof. Michael Gillan and Prof. Dario Alfe at University College London (London, United Kingdom). In 2010, Dr. Cazorla moved to the Institute of Materials Science of Barcelona (Barcelona, Spain) to work under the supervision of ICREA Prof. Massimiliano Stengel; from 2011 to 2014, Dr. Cazorla enjoyed a JAE-DOC Fellowship in the same institution. In 2014, Dr. Cazorla was awarded an ARC Future Fellowship in the School of Materials Science and Engineering at UNSW Sydney (Sydney, Australia), where he has worked until 2020 as a Senior Lecturer. Recently, Dr. Cazorla obtained a Ramón y Cajál Fellowship and returned to the Physics Department of his alma matter institution. Dr. Cazorla’s primary research interests are the application and development of computational techniques to understand and design materials with potential for nanoelectronics and energy conversion/harvesting applications.
Hosted by Mariona Coll and Riccardo Rurali, ICMAB researchers
Register here to attend by Zoom.