In Situ Construction of Built-In Opposite Electric Field Balanced Surface Adsorption for Hydrogen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The hydrogen evolution reaction (HER) is critical for sustainable energy production.
• Optimizing hydrogen adsorption and desorption is key to efficient HER catalysis.
• Current catalysts face challenges in balancing these adsorption/desorption properties.

Purpose of the Study:

• To demonstrate the feasibility of designing built-in opposite electric fields (OEF) for HER catalysis.
• To investigate the Ni3(BO3)2/Ni5P4 heterostructure as a model system for OEF implementation.
• To optimize hydrogen atom adsorption and H2 desorption for enhanced catalytic activity.

Main Methods:

• Density functional theory (DFT) calculations to model electric fields and adsorption energies.
• Electrochemical synthesis of Ni3(BO3)2/Ni5P4 heterostructures.
• Characterization using Grazing Incidence Wide-Angle X-ray Scattering (GIWAXS) and in situ Raman spectroscopy.

Main Results:

• DFT calculations confirmed OEF at the Ni3(BO3)2/Ni5P4 interface, optimizing H adsorption free energy (ΔGH*) near 0.05 eV.
• Experimentally synthesized Ni3(BO3)2/Ni5P4 exhibited surface reconstruction.
• The catalyst achieved a low overpotential of 33 mV at 10 mA cm-2 for HER in alkaline media.
• Exceptional stability was observed for over 360 hours.

Conclusions:

• The built-in opposite electric field (OEF) strategy effectively optimizes HER catalysis.
• The Ni3(BO3)2/Ni5P4 heterostructure demonstrates high performance and stability.
• This OEF design approach offers a promising pathway for advancing electrocatalyst development.