Interfacial electronic structure modulation of CoP nanowires with FeP nanosheets for enhanced hydrogen evolution under alkaline water/seawater electrolytes

Interface engineering is an effective strategy to regulate surface properties and improve the catalytic activities of materials. Here we develop an interface engineered core-shell structure FeP@CoP catalyst, which only requires 50 mV to realize current density of 10 mA/cm(2) with a low Tafel slope of 51.1 mV/dec in 1 M KOH. Density functional theory (DFT) simulations indicate the FeP@CoP interface exhibits optimal H* adsorption energy (0.06 eV) compared with pure-phased CoP (0.26 eV) and pure-phased FeP (-0.18 eV), which is attributed to the significantly electronic structure modulation of Fe and Co atoms at the interface domain. Furthermore, the assembled NiFe LDH@Co3O4/NF||FeP@CoP/NF electrolyzer only demands the voltages of 1.50 and 1.70 V to achieve 10 and 100 mA/cm(2) under 1 M KOH. The electrolyzer also exhibits considerable catalytic performance in alkaline seawater electrolyte. What's more, it also can be driven by a commercial Si solar panel under AM 1.5 G 100 mW/cm(2) illumination. The regulation of interface-effect paves a novel avenue for constructing high-performance catalysts for hydrogen production.

Automated summary

Interface engineering is an effective strategy for improving catalytic activities. In this study, FeP@CoP core-shell catalyst was developed, which showed high current density and low overpotential for water splitting. Density functional theory simulations revealed the optimal adsorption energy at the FeP@CoP interface. Additionally, the catalyst exhibited excellent performance in electrolyte and was able to be driven by a solar panel.