Atomic-layered V₂C MXene containing bismuth elements: 2D/0D and 2D/2D nanoarchitectonics for hydrogen evolution and...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Two-dimensional (2D) vanadium carbide (V₂C) MXenes are theoretically promising for electrocatalytic hydrogen evolution reaction (HER) and nitrogen reduction reaction (NRR).
• Limited experimental exploration exists for V₂C in these applications.

Purpose of the Study:

• To experimentally investigate V₂C MXene-based materials for HER and NRR.
• To synthesize and characterize novel 2D/0D and 2D/2D nanostructures using V₂C and bismuth compounds.

Main Methods:

• Synthesis of 2D/2D V₂C/BiVO₄ (V₂C/BVO) via a hydrothermal method.
• Synthesis of 2D/0D V₂C/Bi (V₂C/Bi) using solid-state annealing.
• Electrocatalytic performance evaluation for HER and NRR.

Main Results:

• V₂C/BVO demonstrated enhanced HER activity in 0.5 M H₂SO₄ compared to pristine V₂C, attributed to increased surface area, active sites, and electron transfer.
• V₂C/BVO exhibited superior stability in acidic media.
• V₂C/Bi achieved high electrocatalytic NRR performance with ammonia production of 88.6 μg h^-1 cm^-2 and 8% Faradaic efficiency at -0.5 V vs. RHE, with excellent long-term stability.

Conclusions:

• The 2D/2D V₂C/BVO nanostructure is a promising electrocatalyst for HER.
• The 2D/0D V₂C/Bi nanostructure shows high efficiency and stability for NRR, outperforming recent MXene-based catalysts.
• The enhanced NRR performance of V₂C/Bi is linked to the effective suppression of the competitive HER.