Band-Gap Tunable 2D Hexagonal (GaN)_1-(ZnO) Solid-Solution Nanosheets for Photocatalytic Water Splitting

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Gallium Nitride-Zinc Oxide (GaN-ZnO) solid solutions are promising visible-light-driven photocatalysts for overall water splitting.
• Efficient water splitting requires minimizing electron-hole recombination, a common limitation in photocatalytic materials.
• Developing 2D nanostructures can reduce charge carrier transport distances, potentially improving photocatalytic efficiency.

Purpose of the Study:

• To synthesize band-gap tunable 2D (GaN)_1-x(ZnO)_x nanosheets using a template reactive strategy.
• To investigate the effect of nanosheet morphology and thickness on photocatalytic activity for water splitting.
• To enhance hydrogen evolution performance through cocatalyst modification.

Main Methods:

• A template reactive strategy was employed to synthesize 2D (GaN)_1-x(ZnO)_x nanosheets.
• The synthesis involved a morphology and structure transformation from hexagonal 2D ZnGa₂O₄ to 2D (GaN)_1-x(ZnO)_x via nitridation.
• The resulting nanosheets were characterized, and their photocatalytic activity was tested after modification with a Rhodium (Rh) cocatalyst.

Main Results:

• The template strategy successfully produced 2D (GaN)_1-x(ZnO)_x nanosheets with a thickness of approximately 14 nm.
• The flowerlike (GaN)_0.89(ZnO)_0.11 nanosheets exhibited enhanced hydrogen evolution rates in pure water (pH 4.5) after Rh cocatalyst modification (1 wt %).
• The reduced carrier transportation path in the thin nanosheets contributed to decreased electron-hole recombination.

Conclusions:

• The template reactive strategy is effective for synthesizing tunable 2D (GaN)_1-x(ZnO)_x nanosheets for photocatalysis.
• The thin 2D morphology and Rh cocatalyst modification significantly enhance the hydrogen evolution performance of (GaN)_1-x(ZnO)_x.
• These findings highlight the potential of engineered (GaN)_1-x(ZnO)_x nanosheets as efficient visible-light-driven photocatalysts for overall water splitting.