Rogé V., Garlisi C., Popa P.L., Menguelti K., Michel M., Vergne C., Wagner E., Maudez W., Benvenuti G., Pistillo B.R., Barborini E.
Journal of Materials Chemistry A, vol. 12, n° 25, pp. 15227-15239, 2024
In this research, we highlight an innovative combinatorial approach to explore the correlation between the elemental composition of SrTiO<sub>3</sub> thin films and their photoelectrochemical characteristics for water splitting. Employing the Chemical Beam Vapor Deposition technique, we successfully synthesized Sr<sub>x</sub>Ti<sub>y</sub>O<sub>z</sub> thin films with varying Sr/Ti compositions, ranging from highly strontium cation deficient (Sr/Ti = 0.3) to rich (Sr/Ti = 2) films, in a single deposition process. A detailed examination of the near-stoichiometric range identified a narrow window wherein the crystalline perovskite structure was maintained. This enabled us to pinpoint the optimal strontium to titanium ratio composition between St/Ti = 0.8 and Sr/Ti = 1.2, resulting in the most efficient photoelectrode. The performance of these photoelectrodes was correlated with the physico-chemical properties of the Sr<sub>x</sub>Ti<sub>y</sub>O<sub>z</sub> films, as investigated through techniques such as X-ray diffraction, ultraviolet-visible absorption spectroscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy.
