Novel Stable 3D Stainless Steel‐Based Electrodes for Efficient Water Splitting

Abstract The stability of electrocatalysts grown on substrates is a significant challenge for the construction of 3‐dimensional (3D) stainless‐steel (SS)‐based electrodes for highly efficient water splitting. This paper presents an efficient and universal process to enhance the interfacial interaction between SS and highly active electrocatalysts for the preparation of 3D electrodes through the formation of an interfacial network of carbon nanotubes (CNTs) on the SS. Nanoscale X‐ray computed tomography and focused ion beam are used to visualize the interface between CNTs and SS, and 3D structure of CNT/SS electrodes. The strongly interconnected CNTs network increases the surface area of the SS support that benefits the modification of highly active electrocatalysts and also serves as an electron/charge‐conductive highway between electrocatalysts and support. The electrocatalysts on CNT/SS further improve hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances, respectively, of the 3D electrodes. While compared to the SS‐based electrodes reported recently, Pt/OxCNT/SS shows the best HER activity over wide pH range and RuO 2 /OxCNT/SS exhibits a comparable OER performance in neutral and alkaline electrolyte. An efficient approach is reported to combine highly active electrocatalysts with SS for the preparation of active and stable 3D electrodes that can be further explored in various areas.