Photoinduced CO₂ and N₂ reductions on plasmonically enabled gallium oxide

Area of Science:

• Materials Science
• Photocatalysis
• Semiconductor Heterostructures

Background:

• ZnO/β-Ga2O3 semiconductors exhibit promising properties for photocatalysis.
• Plasmonic silver (Ag) incorporation can enhance semiconductor performance.
• Efficient charge separation is crucial for photocatalytic efficiency.

Purpose of the Study:

• To synthesize and characterize Ag-containing ZnO/β-Ga2O3 heterostructures.
• To evaluate the photocatalytic performance for CO2 reduction and N2 fixation.
• To elucidate the structure-photoactivity relationship.

Main Methods:

• Synthesis of Ag-containing ZnO/β-Ga2O3 (Ag@GaZn) heterostructures.
• Photocatalytic experiments for CO2 reduction and N2 fixation.
• In situ DRIFTS and Density Functional Theory (DFT) calculations.

Main Results:

• Ag@GaZn showed significantly enhanced photocurrent response compared to Ga and GaZn.
• CO2 photoreduction yielded CO, CH4, and H2, with Ag@GaZn exhibiting the highest AQY.
• N2 fixation by Ag@GaZn produced NH4+ ions at rates 18-fold higher than the Ga sample.
• In situ DRIFTS confirmed the photoactivity for CO2 and N2 conversion.
• DFT calculations provided insights into molecular adsorption on heterostructure planes.

Conclusions:

• Ag@GaZn heterostructures demonstrate excellent photocatalytic activity for CO2 reduction and N2 fixation.
• The enhanced performance is attributed to improved charge separation at new interfaces and inherent vacancies.
• Plasmonic Ag plays a key role in boosting photoactivity and stability.
• The study offers a fundamental understanding for designing efficient semiconductor heterostructures.