Enhanced water splitting over ethylenediaminetetraacetate treated SrTiO₃ photocatalysts with high crystallinity,...

The key elements that influence the properties and capabilities of particulate photocatalysts are their crystallinity, size, and surface active sites. However, simultaneously controlling these three variables remains a challenge. In this study, we present the first exploration into the use of a simple ethylenediaminetetraacetate (EDTA) etching technique to decrease the particle size and increase the surface active sites of photocatalysts while preserving their high crystallinity. By employing SrTiO₃ as a model photocatalyst, we were able to create an ordered step nanostructure on the surface of sintered SrTiO₃. As a result of the EDTA treatment, the particle size was reduced while the crystallinity was maintained. The separation of photogenerated electrons and holes is enhanced by the combination of reduced particle size and high crystallinity. To enhance chemical reaction activities, the organized surface nano-step structures serve as high-activity sites. As a result, when subjected to simulated light irradiation, the EDTA-treated SrTiO₃ samples demonstrate improved photocatalytic performance for water splitting into H₂ and O₂ in a stoichiometric amount that is 3.8 times greater than that of untreated SrTiO₃. Since EDTA interacts with most metals, this simple EDTA etching technique has the potential to be further developed to modify additional photocatalysts with exceptional performance for a variety of applications.