Abstract
Identification of active and stable dual-functional electrocatalyst is a key obstacle for producing clean hydrogen fuel. Herein, we report a single-step fabrication of nickel-yttria stabilized zirconia (Ni-YSZ) 3D micro-pattern through atmospheric plasma spray as a dual-functional electrocatalyst for overall water splitting. This 3D micro-pattern strategy improves the mass diffusion pathway and active surface area, resulting in good electrocatalytic activity towards oxygen and hydrogen evolution reactions (OER and HER). Although YSZ alone shows little catalytic activity, Ni decorations enhances the activity towards OER and HER in alkaline solution. Using Ni-YSZ as a dual-functional electrocatalyst, it reaches a current density of 10 mA cm−2 at the potential of 1.70 V, 1.65 V, and 1.67 V after 0 h, 100 h, and 200 h of durability tests. Besides, electrochemical impedance spectroscopy (EIS) spectra analyzed by genetic programming is monitoring the resistance contributed by several relaxations and provides the information about its changes with durability tests and Ni contents. This study opens a new strategy to enhance the water-splitting performance and to analyze the EIS data of electrocatalytic systems.