A Highly Active and Durable Hierarchical Electrocatalyst for Large-Current-Density Water Splitting
Yanhao Dong, Zhiping Deng, Hao Zhang, Guangyi Liu, Xiaolei Wang
Abstract
Designing bifunctional catalysts with high current densities under industrial circumstances is crucial to propelling hydrogen energy with a boost from fundamental to practical application. In this work, heterojunction nanowire arrays consisting of manganese oxide and cobalt phosphide (denoted as MnO-CoP/NF) are designed to meet the industrial demand by regulating the synergic mass transport and electronic structure coupling with numerous nano-heterogeneous interfaces. The optimal MnO-CoP/NF electrode exhibits remarkable bifunctional electrocatalytic performance with overpotentials of 259.5 mV for hydrogen evolution at a large current density of 1000 mA cm –2 and 392.2 mV for oxygen evolution at 1500 mA cm –2 . Moreover, the MnO-CoP/NF electrode demonstrates superior durability and an ultralow voltage of 1.76 V at 500 mA cm –2, outperforming that of a commercial RuO 2 ||Pt/C electrode. This work sheds light on the design of metallic heterostructures with optimized interfacial electronic structures and a high abundance of active sites for practical industrial water splitting applications.