Atomically Dispersed Platinum Modulated by Sulfide as an Efficient Electrocatalyst for Hydrogen Evolution Reaction.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Single-atom catalysts (SACs) offer ultimate atom utilization efficiency for electrocatalysis.
• Optimizing metal atom coordination is key to enhancing SAC activity and selectivity.
• Transition metal sulfides are promising supports for SACs.

Purpose of the Study:

• To design and synthesize a novel single-atom catalyst for enhanced electrocatalytic performance.
• To investigate the electronic and structural properties influencing catalytic activity.
• To evaluate the hydrogen evolution reaction (HER) performance of the fabricated catalyst.

Main Methods:

• Design of a transition-metal sulfide (Ni₃S₂) support with engineered Ni vacancies.
• Anchoring of atomically dispersed platinum (Pt_SA) onto the Ni₃S₂ support.
• Theoretical calculations to elucidate electronic structure and catalytic mechanisms.
• Fabrication of a 3D nanostructure (Pt_SA-Ni₃S₂@Ag NWs) for enhanced conductivity.

Main Results:

• The Pt-Ni₃S₂ interaction modifies electronic properties, enhancing H₂O adsorption and optimizing H binding.
• Orbital hybridization between S-3p and Pt-5d creates metallic Pt sites, improving reaction kinetics.
• The Pt_SA-Ni₃S₂@Ag NWs catalyst achieved a high mass activity of 7.6 A mg^-1 for HER.
• The catalyst exhibited 27 times higher activity than commercial Pt/C.

Conclusions:

• Engineered Ni vacancies in Ni₃S₂ effectively anchor atomically dispersed Pt.
• The unique electronic structure and metallic Pt sites significantly enhance HER kinetics.
• The developed Pt_SA-Ni₃S₂@Ag NWs represent a highly efficient electrocatalyst for HER.