Wet chemical fabricating of 3D printed electrodes for overall water splitting

Abstract

Electrocatalytic water splitting is a key technology for sustainable energy. To-date, designing electrodes from the atomic level to the nano- and microstructure is a promising route to address challenges ranging from catalytic activity and stability to mass transport and gaseous product release. Thus, developing facile routes to well-defined electrodes with high activity and stability is still a challenge. As an additive fabrication technology, 3D printing enables the fabrication of electrochemical devices and electrodes in a novel way. Here, we developed wet chemical methods, including simple electroless plating and corrosion, for the preparation of metallized 3D printed electrodes for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). By doing HER on Ni-plated electrodes, an unexpected activation process was observed to be facilitated by W and P dopants. The electrodes for OER were prepared by corroding Ni-plated electrodes in an aqueous solution containing Fe3+. The resulting electrodes exhibit relatively low overpotentials in alkaline aqueous solution for HER (42 mV, current density j = 10 mA/cm2) and OER (220 mV, current density j = 10 mA/cm2), respectively.