Superaerophilic/superaerophobic cooperative electrode for efficient hydrogen evolution reaction via enhanced mass transfer.

Hydrogen evolution reaction (HER), as an effective method to produce green hydrogen, is greatly impeded by inefficient mass transfer, i.e., bubble adhesion on electrode, bubble dispersion in the vicinity of electrode, and poor dissolved H 2 diffusion, which results in blocked electrocatalytic area and large H 2 concentration overpotential. Here, we report a superaerophilic/superaerophobic (SAL/SAB) cooperative electrode to efficiently promote bubble transfer by asymmetric Laplace pressure and accelerate dissolved H 2 diffusion through reducing diffusion distance. Benefiting from the enhanced mass transfer, the overpotential for the SAL/SAB cooperative electrode at -10 mA cm -2 is only -19 mV, compared to -61 mV on the flat Pt electrode. By optimizing H 2 SO 4 concentration, the SAL/SAB cooperative electrode can achieve ultrahigh current density (-1867 mA cm -2 ) at an overpotential of -500 mV. We can envision that the SAL/SAB cooperative strategy is an effective method to improve HER efficiency and stimulate the understanding of various gas-involved processes.