Dinh-Tu Luu-DangNgan My TranHan Ngoc-Doan HuynhTuan-Anh NguyenDinh Quan NguyenWen-Yueh YuMarjeta Maček KržmancVan-Han DangJEFFREY CHI-SHENG WU2025-03-202025-03-202025-04https://www.scopus.com/record/display.uri?eid=2-s2.0-85214932626&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/725898Background: The solar-driven photocatalytic seawater splitting process for simultaneous hydrogen and oxygen gas has garnered significant attention as a promising technique for generating eco-friendly chemical fuels. This approach is particularly attractive because of its low cost, and the ability to utilize abundant sunlight and seawater resources. Methods: The Rh@Cr2O3/SrTiO3:Al (RCSTOA) heterojunction photocatalyst, synthesized via flux technique and photodeposition treatment, possessed distinctive physicochemical properties and exhibited high photocatalytic seawater-splitting performance. Significant findings: The findings emphasized that the thin layers of Rh@Cr2O3 structure (5–20 nm) firmly intimate with a SrTiO3:Al (STOA) photocatalyst significantly enhanced the seawater-splitting process without requiring any sacrificial agents. Hydrogen and oxygen evolution rates (HER and OER) in natural seawater splitting increased significantly, achieving 263 and 130 µmol.g−1.h−1, respectively maintaining photostability after five consecutive cycles under simulated sunlight illumination. Notably, under the synergy of I−-anion solution, the HER improved to 332 µmol.g−1.h−1 without any OER, highlighting potential for H₂/O₂ separation. These findings are expected to advance seawater splitting technology and contribute to potential H2/O2 separation techniques in this field.Core-shell cocatalyst structureH2/O2 separationHydrogen productionOverall photocatalytic seawater splittingShuttle mediators[SDGs]SDG14journal article10.1016/j.jtice.2025.105971