Self-Enhancement of Water Electrolysis by Electrolyte-Poled Ferroelectric Catalyst

Efficient and durable electrocatalysts with superioractivity areneeded for the production of green hydrogen with a high yield andlow energy consumption. Electrocatalysts based on transition metaloxides hold dominance due to their abundant natural resources, regulablephysical properties, and good adaptation to a solution. In numerousoxide catalyst materials, ferroelectrics, possessing semiconductingcharacteristics and switchable spontaneous polarization, have beenconsidered promising photoelectrodes for solar water splitting. However,few investigations noted their potential as electrocatalysts. In thisstudy, we report an efficient electrocatalytic electrode made of aBiFeO(3)/nickel foam heterostructure, which displays a smalleroverpotential and higher current density than the blank nickel foamelectrode. Moreover, when in contact with an alkaline solution, thebond between hydroxyls and the BiFeO3 surface induces alarge area of upward self-polarization, lowering the adsorption energyof subsequent adsorbates and facilitating oxygen and hydrogen evolutionreaction. Our work demonstrates an infrequent pathway of using functionalsemiconducting materials for exploiting highly efficient electrocatalyticelectrodes.