Hydrogen evolution reactions boosted by bridge bonds between electrocatalysts and electrodes.

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Interfacial interactions are crucial for electrochemical energy devices but are poorly understood.
• The influence of these interactions on device performance, particularly the hydrogen evolution reaction (HER), requires further investigation.

Purpose of the Study:

• To investigate the interfacial interactions between cobalt disulfide (CoS2) nanobelts and titanium (Ti) electrodes.
• To correlate these interactions with the performance of the hydrogen evolution reaction (HER).
• To provide insights for designing high-performance electrochemical devices.

Main Methods:

• Preparation of CoS2 nanobelts on Ti foil via in situ chemical conversions.
• Characterization studies to analyze interfacial properties.
• Density functional theory (DFT) calculations to support experimental findings.

Main Results:

• Identification of interfacial bridge bonds (Ti-S-Co and Ti-O-Co) in a covalent form.
• CoS2 nanobelts/Ti exhibited enhanced HER performance (higher activity, lower overpotential/Tafel slope) compared to solution-derived counterparts.
• Interfacial bonds improved mechanical integrity and facilitated charge transfer.

Conclusions:

• Covalent interfacial bridge bonds are key to enhanced HER performance in CoS2 nanobelts/Ti electrodes.
• These bonds act as efficient charge transfer channels, ensuring stable electron transfer for HER.
• The findings offer a new perspective on electrode-material interfaces for designing advanced electrochemical energy devices.