Activating inert copper hydroxide by coordination effect of stoichiometric nitrate for efficient hydrogen evolution...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The hydrogen evolution reaction (HER) is crucial for clean energy but is limited by poor hydrogen adsorption in metal hydroxides, requiring high overpotentials.
• Conventional copper hydroxide (Cu(OH)₂) exhibits weak hydrogen adsorption, hindering its efficiency in HER applications.

Purpose of the Study:

• To enhance the HER activity of copper hydroxide through coordination engineering.
• To investigate the synergistic effects of nitrate ligands and cobalt doping on copper hydroxide's electrocatalytic performance.

Main Methods:

• Coordination engineering strategy involving the introduction of nitrate ligands to copper hydroxide.
• Synthesis of cobalt-doped copper hydroxide with nitrate ligands (Co-CuHN) via facilitated doping.
• Experimental and theoretical analyses (including DFT) to study electronic structure and reaction mechanisms.

Main Results:

• The Co-CuHN material exhibited an expanded lattice structure and modulated electronic properties due to nitrate and cobalt co-doping.
• A significantly reduced water dissociation energy barrier (0.54 eV) and optimized Gibbs free energy for hydrogen adsorption were observed.
• Co-CuHN demonstrated a low Tafel slope (40.0 mV dec^-1) and a low overpotential (18 mV at 10 mA cm^-2), outperforming Cu(OH)₂.

Conclusions:

• Anion coordination regulation is an effective strategy to improve the HER performance of copper hydroxide.
• The synergistic effect of nitrate and cobalt doping enhances catalytic activity by optimizing surface adsorption and lowering energy barriers.
• This work offers a new pathway for designing advanced electrocatalysts for efficient hydrogen production.