(Ni,Co)Se@Ni(OH)₂ heterojunction nanosheets as an efficient electrocatalyst for the hydrogen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Heterogeneous structures enhance electrocatalytic activity by improving active sites and electron transfer.
• Developing efficient electrocatalysts is crucial for energy conversion technologies like hydrogen production.

Purpose of the Study:

• To design and synthesize nickel foam-supported nickel-cobalt selenide/hydroxide (NCS@NH) heterojunction nanosheets.
• To investigate the effect of the heterojunction structure on electrocatalytic activity, specifically for the hydrogen evolution reaction (HER).

Main Methods:

• A two-step synthesis involving hydrothermal method followed by selenization.
• Fabrication of NiCo2S4@Ni(OH)2 (NiCo2S4@NH) nanosheets on nickel foam.
• Conversion of NiCo2S4@NH to NCS@NH heterogeneous nanosheets via selenization.

Main Results:

• The synthesized NCS@NH nanosheets exhibit a heterojunction interface, accelerating electron transfer and improving catalytic activity.
• Optimized Co doping (2 mmol) resulted in superior HER properties, requiring 253 mV to achieve 100 mA cm-2.
• The material demonstrated excellent stability, maintaining performance for 24 hours.

Conclusions:

• The NCS@NH heterojunction nanosheets effectively boost electrocatalytic performance for HER.
• The rational design of heterostructures is a promising strategy for developing advanced electrocatalysts.
• The optimized material shows potential for practical applications in hydrogen production.