Monometallic interphasic synergy via nano-hetero-interfacing for hydrogen evolution in alkaline electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic synergy is crucial for efficient energy conversion.
• Typically, synergy arises from intermetallic interactions between different metals.
• Monometallic systems offer a simpler yet potentially effective route to achieve synergy.

Purpose of the Study:

• To demonstrate the effectiveness of interphasic synergy in monometallic structures.
• To investigate interphasic synergy between Ni(OH)2 and Ni-N/Ni-C phases for alkaline hydrogen evolution.
• To develop novel monometallic electrocatalysts for water splitting.

Main Methods:

• Fabrication of Ni(OH)2@Ni-N/Ni-C hetero-hierarchical nanostructures.
• Electrochemical characterization of the catalyst for hydrogen evolution reaction (HER) in alkaline media.
• Analysis of electronic structure and intermediate adsorption using density of states and adsorption energy calculations.

Main Results:

• The Ni(OH)2@Ni-N/Ni-C nanostructure exhibits enhanced HER performance.
• Overpotentials were reduced by 102 mV and 113 mV at -10 and -100 mA cm-2, respectively, compared to monophasic Ni(OH)2.
• The synergy lowers energy barriers for hydrogen and hydroxyl intermediate adsorption/desorption and facilitates charge redistribution.

Conclusions:

• Interphasic synergy in monometallic catalysts is a viable and effective strategy for electrocatalysis.
• The developed Ni(OH)2@Ni-N/Ni-C catalyst shows significant potential for alkaline water splitting.
• This approach offers a new direction for designing advanced electrocatalysts for energy applications.