Advanced bubble control engineered electrodes for high-efficient hydrogen evolution

As the demand for sustainable energy continues to rise, the development of high-efficient hydrogen (H₂) production via water electrolysis based on precise bubble manipulation is garnering significant attention. This study presents a novel three-dimensional (3D) micro-cone engineered electrode to enhance the ion exchange rate and catalytic active site regeneration during the electrochemical water splitting process, thereby improving H₂ production rates. The unique micro-cones enables precise manipulation of H₂ bubble behavior, which achieves directional transport from nucleation to detachment at the top within a mere 224 ms. Simultaneously, the bubble manipulation performance of micro-cones with varying geometric configurations and dimensional parameters is investigated. The optimal bubble manipulation performance is achieved when the micro-cones have a circular base with a diameter of 100 μm, a height of 300 μm, and an array center distance of 100 μm. The performance of the 3D micro-cone engineered electrode outperforms conventional commercial electrodes, with its capacitance (C_dl) value reaching 35.1 mF cm⁻², which is significantly higher than those of Ni foam and Ni-CP. Additionally, under a 1.7 V vs. RHE condition, the electrode achieves a current density of 80 mA cm⁻², with a H₂ collection rate 32.3 % higher than that of a Ni foam under identical conditions. Large-scale outdoor experiments driven by solar energy further confirm the scalability and stability of the micro-cone engineered electrodes, which is capable of producing substantial H₂ quantities over extended periods without bubbles blockage. The large-area micro-cone electrodes, when operated continuously under high outdoor current density, still exhibit excellent H₂ production and bubble directional manipulation stability. This research highlights the transformative impacts of advanced electrode design on water electrolysis efficiency and H₂ bubbles manipulation, offering new insights for ultra-high efficient sustainable H₂ production.