Constructing S-deficient nickel sulfide/N-doped carbon interface for improved water splitting activity

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Transition-metal sulfides are promising electrocatalysts for water splitting.
• Their application is limited by phase reconstruction and poor durability.
• Developing stable and efficient catalysts is crucial for water electrolysis.

Purpose of the Study:

• To develop a robust nickel sulfide (NiS) nanoarray catalyst protected by nitrogen-doped carbon (NiS-NC@NF).
• To investigate the enhanced electrocatalytic performance and durability of NiS-NC@NF for water splitting.
• To understand the role of the NiS/N-doped carbon interface in catalyst stability and activity.

Main Methods:

• Synthesis of NiS nanoarrays on foam nickel (NF) protected by N-doped carbon via in situ transformation.
• Electrochemical characterization including overpotential measurements for hydrogen and oxygen evolution reactions.
• Fabrication and testing of a water electrolyzer using NiS-NC@NF as both anode and cathode.

Main Results:

• Achieved low overpotentials of 88.0 mV for hydrogen evolution and 170.0 mV for oxygen evolution at 10.0 mA cm⁻².
• Demonstrated controlled regulation of NiS reconstruction by the N-doped carbon matrix.
• Constructed a water electrolyzer with NiS-NC@NF exhibiting a low cell voltage of 1.51 V for alkaline water splitting.

Conclusions:

• The NiS-NC@NF catalyst exhibits superior electrocatalytic activity and stability for water splitting.
• The in situ constructed NiS/N-doped carbon interface plays a key role in tuning catalyst properties.
• This work offers a promising strategy for developing durable and efficient electrocatalysts for clean energy applications.