Ir-IrO2 with heterogeneous interfaces and oxygen vacancies-rich surfaces for highly efficient oxygen evolution reaction
Gaoyang Liu, Faguo Hou, Xingdong Wang, Baizeng Fang
Abstract
The development of efficient and stable catalysts for oxygen evolution reaction (OER) has recently attracted much attention, and the major challenge of current research is to offer fast kinetics and enhance the durability in a harsh oxidising environment. Herein, an effective strategy is developed to construct a unique heterogeneous interface between Ir nanoclusters and IrO 2 via a facile and scalable chemical reduction method, followed by the thermal treatment under Ar atmosphere. Both the transmission electron microscope and X-ray photoelectron spectroscopy results revealed that the as-prepared Ir-IrO 2 has been engineered with heterogeneous interfaces and oxygen vacancies-rich surfaces. Benefited from newly-formed active surfaces and the oxygen vacancies-rich surfaces, the Ir-IrO 2 catalyst exhibits increased catalytic active sites and enhanced catalytic activity towards the OER compared with the pure IrO 2 and commercial IrO 2 . The over-potential of the Ir-IrO 2 is ca. 329 mV at 10 mA cm −2 , and the mass activity is ca. 1851 A g IrO2 −1 at 1.60 V (vs. RHE), about 2.4 times that of the commercial IrO 2 (ca. 779 A g IrO2 −1 ). In addition, both the improved catalytic performance and durability for the OER is further confirmed in PEM water electrolysis cell.