Solid-State Proton Donors in Hydroxyl-Rich Ni₃Ge₂O₅(OH)₄ for Solar-Driven Hydrogen Evolution

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Hydrogen evolution reaction (HER) is crucial for sustainable energy.
• Existing methods often require cocatalysts or sacrificial agents.
• Developing efficient, cocatalyst-free systems is a key challenge.

Purpose of the Study:

• To demonstrate a novel solar-driven gas-solid system for hydrogen production.
• To utilize hydroxyl-rich Ni3Ge2O5(OH)4 as a photocatalyst.
• To investigate the role of lattice hydroxyls and oxygen vacancies in enhancing proton activity.

Main Methods:

• Photocatalytic water splitting using Ni3Ge2O5(OH)4 in a gas-solid system.
• Investigation of the kinetic self-activation mechanism.
• Analysis of hydroxyl regeneration via water dissociation at oxygen vacancies.

Main Results:

• Achieved a high cocatalyst-free H2 yield of 311.8 μmol g−1.
• The gas-solid system outperformed traditional triphasic systems by 35 times.
• Demonstrated significantly higher H2 production compared to systems using sacrificial agents.

Conclusions:

• The developed gas-solid system offers a highly efficient pathway for sustainable hydrogen production.
• Lattice hydroxyls and oxygen vacancies are critical for enhanced proton activity and catalyst regeneration.
• This research provides insights for designing advanced photocatalysts for energy applications.