Mixed B-site ruddlesden-popper phase Sr2(Ru Ir1-)O4 enables enhanced activity for oxygen evolution reaction

Development of high performance electrocatalysts for oxygen evolution reaction (OER) in acidic media remains a challenge direct water splitting using an electrolyzer. Recently, Ruddlesden-Popper phase Sr2IrO4 was discovered to be efficient OER catalyst because its unique structure, which consists layers both rock salt and perovskite phases simultaneously. In this study, we prepared series B-site mixed, Sr2(RuxIr1?x)O4 examined their electrocatalytic properties media. Through partial substitution Ru the materials, achieved much enhanced electrocatalysts, among Sr2(Ru0.5Ir0.5)O4 exhibited best catalytic activity with current density 8.06 mA/cm2 at 1.55 V Tafel slope 47 mV/dec. This is three times higher than that Sr2IrO4. The mixed retained good stability conditions > 24 h 10 mA/cm2. A range techniques were used characterize crystal electronic structures samples. Our data indicate improved can correlated formation level hydroxyl groups overlap between Ir/Ru 4d O 2p orbitals, revealing new way design by regulating composition structures.