Enhanced water splitting over ethylenediaminetetraacetate treated SrTiO3 photocatalysts with high crystallinity, reduced size, and surface nanostructure.

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.