Self-sacrificial templated-directed synthesis of an ultrathin 0D/2D FeNi3-NC/NiFeOx Schottky junction as a hydrogen evolution reaction electrode for alkaline seawater electrolysis

Abstract

Seawater, a plentiful natural resource, is promising for hydrogen production compared to traditional electrocatalytic methods based on high-purity freshwater. This strategy shift addresses the challenge of limited freshwater resources and holds significant potential for desalination applications. Hence, identifying effective electrocatalysts for seawater electrolysis is imperative to alleviate freshwater resource scarcity and achieve large-scale hydrogen production. Herein, we report a catalyst comprising zero-dimensional (0D) nitrogen-doped carbon-coated FeNi₃ nano-particles (FeNi₃-NC) grown on NiFeO_x nano-sheets for the hydrogen evolution reaction in alkaline seawater. The combination of FeNi₃-NC and NiFeO_x significantly enhances interfacial interactions, resulting in an elevated rate of electron transfer. The FeNi₃-NC/NiFeO_x catalyst requires a low overpotential of 65 mV to achieve a current density of 10 mA cm⁻² in alkaline seawater. In addition, the electrolytic cell constructed using it and its precursor also exhibits excellent water-splitting characteristics and it exhibits remarkable long-term stability and corrosion resistance. This discovery presents an innovative approach for designing zero-dimensional/two-dimensional catalysts to facilitate large-scale hydrogen production through seawater electrolysis.