Multiscale Hierarchical Structured NiCoP Enabling Ampere-Level Water Splitting for Multi-Scenarios Green Energy-to-Hydrogen Systems

Efficient and stable low-cost catalysts are seriously lacking for industrial water electrolysis at large-current-density. To meet industrial-scale hydrogen production, fully utilized active sites by a rational structure design is an attractive route. Herein, dynamic microstructure manipulation of bimetallic phosphide NiCoP is conducted. Among different microstructures for NiCoP, as-obtained NiCoP-120 at hydrothermal temperature of 120 degrees C, shows a special multiscale hierarchical structure from 3D-nickel foam substrates, 2D-nanosheets to 1D-nanoneedles, which is conducive to efficient utilization of active sites and rapid gas release, thus manifesting outstanding electrocatalytic activities and stability as required by industry. To reach a current density of 10 and 1000 mA cm(-2) for the hydrogen evolution reaction (HER), NiCoP-120 requires ultra-low overpotentials of 56 and 247 mV, respectively. Particularly, as a bifunctional catalyst, it only needs 1.981 V to drive the 1 A cm(-2) overall water splitting and can maintain stable output for 600 h, which is superior to almost all reported non-noble metal catalysts. Moreover, its application prospect in integrated green energy-to-hydrogen systems, including sunlight, wind, thermal, and lithium cells, is well demonstrated. This work provides a guiding strategy for the design of industrial water electrolysis catalysts and the establishment of an externally driven water-splitting hydrogen production system.