Redox Active Material Development and Testing for Efficient Solarthermal Water Splitting

Solar thermal water-splitting (STWS) is a potential solution for global climate change and energy dependence issues as it is a renewable and carbon neutral source of hydrogen, an energy-dense fuel. While active materials already exist for STWS, continued material development for improved hydrogen production capacity, faster kinetics, and long-term stability is needed to improve the feasibility of STWS on a large scale. Perovskites (ABO₃) and spinels (AB­₂O₄) have shown promise as active materials for improving the efficiency of solarthermal water-splitting. The complex perovskite Sr_0.4La_0.6Mn_0.6Al_0.4O₃ (SLMA), the hercynite (FeAl₂O₄) spinel, and the most well-studied STWS material ceria have all been separately shown to produce hydrogen, but comparisons between these studies are difficult due to different experimental conditions. These three materials were tested under the same conditions and compared for both thermodynamic and kinetic viability. Novel binary perovskites and spinels were also chosen using an efficient screening method with density functional theory. These materials were synthesized, fully characterized, and tested for hydrogen production capacity and redox kinetics using a stagnation flow reactor and thermogravimetric analysis.