Controlled Element Specific Nanoscale Domains by Self‐Assembly for High Performance Bifunctional Alkaline Water Splitting Catalyst
Hua Fan, Vivek Maheshwari
Abstract
Abstract A stable bifunctional water‐splitting catalyst can simplify the development of alkaline medium electrolyzers. In this study, a catalytic material with controlled nanoscale domains of Pt and Ni is formed by a self‐assembly process at room temperature. The final structure of the catalyst is achieved through two‐stage transformation, first is the formation of Pt‐Ni nanoscale domains and then inducing Ni to higher oxidation states. The material has a nanowire‐like morphology at the macroscale, which ensures rapid kinetics and mass transfer. The results prove that the nanoscale domains of Pt, Ni, and Ni 2+ and Ni 3+ with close interfacing are crucial for the performance of the electrocatalyst and ensure the presence of Ni in a high oxidation state, leading to both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activity. The catalyst has a low overpotential and ultralow Tafel slope for both HER and OER, 13.7 and 32 mV dec −1 , respectively, crucial for high power applications.