Dual-Functional Schottky-Barrier-Free Plasmonic TiN/TiO₂ Photocatalyst for Efficient NH₃ and H₂ Production

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Titanium nitride (TiN) offers high charge carrier density and low work function, addressing limitations of traditional photocatalysts.
• Developing efficient photocatalysts is crucial for sustainable energy and chemical synthesis.

Purpose of the Study:

• To synthesize a novel Schottky-barrier-free plasmonic photocatalyst (SBFPP) based on TiN/TiO2 nanoparticles.
• To investigate the role of oxygen vacancies and defect states in enhancing photocatalytic activity.

Main Methods:

• Synthesis of TiN/TiO2 nanoparticles (NPs) via oxidation of commercial TiN NPs.
• Characterization of material properties, including oxygen vacancy concentration and light absorption.
• Theoretical calculations to understand electronic structures and charge carrier dynamics.
• Evaluation of photocatalytic performance for nitrogen fixation and hydrogen generation.

Main Results:

• TiN NPs oxidized at 400 °C for 2 h (TiN-2) exhibited high oxygen vacancy concentration and broad light absorption.
• Oxygen vacancies and nitrogen dopants in TiO2 create defect electronic states facilitating hot electron migration from TiN.
• The SBFPP demonstrated efficient photocatalytic nitrogen fixation and hydrogen generation.
• A TiN/TiO2 NP-based film enhanced nitrogen fixation performance by approximately 4.4 times.

Conclusions:

• The developed TiN/TiO2 SBFPP effectively utilizes hot charge carriers and defect states for enhanced photocatalysis.
• The study presents a promising strategy for designing advanced plasmonic photocatalysts.
• This work facilitates practical applications in photocatalysis, particularly for nitrogen fixation and hydrogen production.