A unique heterostructure of MOF-derived Fe2O3 as core and P doping NixCoy-LDH as shell for enhanced electrocatalytic hydrogen evolution

Hydrogen (H2) has been regarded as one of the most promising energy owing to its high energy density, zero-carbon emissions and renewable nature. Electrolyzing water is a clean and effective pathway to obtained hydrogen. Developing high-performance, economical and stable electrocatalyst for hydrogen evolution reaction is particularly necessary to meet the growing demand for hydrogen. Herein, a unique core-shell heterostructure of Fe2O3@P-NixCoy-LDH (x/y = 1:1, 1:2 and 2:1) was designed and constructed by MOF-derived Fe2O3 as core and P doping NixCoy-LDH as shell. Fe2O3@P-NixCoy-LDH (x/y = 1:2) showed the best hydrogen evolution activity, with a low hydrogen evolution overpotential of 223 mV and a Tafel slope of 81.1 mV·dec−1 at 10 mA cm−2 current density. The excellent electrocatalytic activity could be attributed to the synergistic effect of Fe2O3, NixCoy-LDH, and the doping P, as well as the unique core-shell heterostructure. Fe2O3 derived from Fe-MOF and NixCoy-LDH provided diverse and abundant metal catalytic sites. Meanwhile, Fe2O3 as the core acted as a uniform matrix for the dispersion of NixCoy-LDH, exposing more active catalytic-sites and accelerating the electron transfer. The doping P effectively modulated the electronic structure of electrocatalysts, promoting the hydrogen evolution.