Self-Supporting Hierarchical Carbon Network Loaded with NiW Nanoparticles for Efficient Hydrogen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Water splitting generates hydrogen energy from renewables, vital for a low-carbon economy.
• Platinum-based catalysts for hydrogen evolution reaction (HER) are costly, necessitating alternatives.
• Developing efficient non-noble metal catalysts is essential for affordable hydrogen production.

Purpose of the Study:

• To synthesize and characterize a novel composite catalyst for efficient hydrogen evolution reaction (HER).
• To investigate the synergistic effects of tungsten doping and nanostructure on catalytic activity.
• To evaluate the catalyst's performance and stability in an alkaline electrolyte.

Main Methods:

• Co-pyrolysis of Ni-BDC-loaded carbon cloth (CC) with urea to form W-doped Ni nanoparticles embedded in carbon nanotubes (CNT) and porous carbon (PC) on CC (NiW-CNT/PC/CC).
• Electrochemical characterization of the catalyst for HER activity in KOH.
• Stability testing over extended periods.
• Computational simulations to understand the electronic structure modifications due to W doping.

Main Results:

• The NiW-CNT/PC/CC composite demonstrated excellent HER activity.
• A low overpotential of 45 mV was required to achieve a current density of 10 mA cm⁻².
• The catalyst exhibited remarkable stability, lasting over 40 hours.
• Simulation calculations revealed that W doping optimizes Ni's electronic structure, lowering the d-band center and weakening hydrogen adsorption, thereby reducing the HER barrier.

Conclusions:

• The developed W-doped Ni catalyst offers a promising, cost-effective alternative to noble metal catalysts for HER.
• The synergistic effects between W, Ni, CNT, and PC contribute to the enhanced catalytic performance.
• This material holds potential for advancing the hydrogen economy through efficient and stable water splitting.