Photocatalytic hydrogen production using layered perovskite oxides

Fossil fuels have a known impact on environmental pollution, and there is a possible scarcity of these fuels in the future. Because of this reason, cleaner and more abundant fuels may be preferred for substitution. Hydrogen, an eco-friendly and promising fuel obtained from electrolysis, is a strong candidate for this purpose. Since solar energy is renewable, electrolyzing water using semiconductors is a sustainable approach. The photocatalytic water splitting reaction can be done by using perovskite oxides, and there are many examples of perovskite oxide materials that can be found in the literature for this purpose. Among these perovskite oxides, layered perovskite oxides stand out because of their chemical stability, tunable morphology, and low-cost precursor chemicals. Sr2TiO4 and KCa2NaNb4O13 are layered perovskite oxides, which have a limited number of studies in the literature, were inspected for their hydrogen evolution capability in this dissertation. The stated molecular structures were studied both with and without dopants to determine their hydrogen evolution rates. Adding additives to a photocatalyst is a widely used method for bandgap engineering. In the study, the effect of copper and nitrogen addition was tested for Sr2TiO4 without the addition of a cocatalyst. Noble metals (Pt, Pd, Ru, Rh) were added to KCa2NaNb4O13 during the synthesis instead of being added later, and hydrogen production rates were evaluated. In addition, proton exchange method was used to increase the surface area of KCa2NaNb4O13 and change its electronic structure. The structural analysis methods, optical measurements, and hydrogen evolution tests were performed on these materials to evaluate their properties. According to the results, both materials were successfully synthesized, their bandgap changes were determined, and their hydrogen production rates increased after the doping and proton exchange processes.