Highly active, durable and pH-universal hybrid oxide nanocrystals for efficient oxygen evolution

Abstract

The development of an active, durable, and low-cost catalyst remains hitherto a grand challenge in energy conversion technologies. Herein, hybrid Ptx–NiMnO₃ nanocrystals (NCs) (x = 0.1, 0.5, and 1.0 mM) were synthesized by a modified citrate-gel approach and utilized as efficient catalysts towards the oxygen evolution reaction (OER). The results showed that the size of Ptx–NiMnO₃ NCs decreases with increasing the initial concentration of Pt. Meanwhile, the OER activity and durability of the as-synthesized Pt–NiMnO₃ under different pH conditions are found to be Pt-content-dependent. Particularly, Pt1–NiMnO₃ showed superior OER efficiency relative to its counterparts Pt0.5–NiMnO₃, Pt0.1–NiMnO₃, NiMnO₃, and commercial Pt/C at different pH values, ascribed to the size, morphology, and composition effects as confirmed via XRD, XPS and electrochemical characterization.