Hydrolytic Stability, Crystal Structure, and Photocatalytic Properties of Layered Perovskites K _{2− <i>x</i>} H <i> _x </i> Eu ₂ Ti ₃ O ₁₀ (0 ≤  <i>x</i>  ≤ 2)

A series of layered perovskites K 2− x H x Eu 2 Ti 3 O 10 (0 ≤ x ≤ 2) belonging to the Ruddlesden–Popper family of phases was synthesized using solid‐state and ion exchange methods. The phase and chemical purity of the compounds were proved by X‐ray diffraction and energy‐dispersive X‐ray microanalysis. The hydrolytic stability of the K 2 Eu 2 Ti 3 O 10 compound was studied upon contact with air and aqueous solutions. The structural changes were determined using differential thermal analysis and IR. The protonated form H 2 Eu 2 Ti 3 O 10 was obtained by leaching the potassium‐containing phase in a heated hydrochloric acid solution. The crystal structure of K 2 Eu 2 Ti 3 O 10 was refined using the Rietveld method. Structural distortions have been quantitatively described. The optical bandgap, valence band edge, and conduction band edge potentials of the obtained compounds were calculated from diffuse reflectance spectroscopy data. A photocatalytic experiment of methylene blue degradation under ultraviolet light was conducted.