3D-printed pyramid nickel-based electrode enabling directional bubble traffic and electrolyte flow for efficient hydrogen evolution

For efficient and stable large-scale water electrolysis, practical industrial electrodes should meet the following characteristics: high activity, structural stability , and fast bubble removal. Here we report a structured electrode (NiS–Co–NiP) prepared via 3D printing of nickel-based substrate and subsequent electrodeposition for the hydrogen evolution reaction (HER). With unique 3D nanosheets , the NiS–Co–NiP electrode exhibits large electrochemical surface area (ECSA), strong hydrophilicity, high mechanical strength and electrical conductivity , delivering outstanding HER activity. It requires low overpotentials of 134 mV and 169 mV to achieve the current densities of 100 mA cm −2 and 300 mA cm −2 , respectively. Moreover, rational design of the NiS–Co–NiP electrode in pyramidal geometry facilitates directional bubble transport and electrolyte flow, resulting in superior stability of 350 h at a current density of 150 mA cm −2 . This work demonstrates a new approach for manufacturing binder-free structured electrode of excellent HER performance at high current densities.