Mechanistic insights into evolution of Schottky junctions on metal nanoparticle-loaded Mo-doped TiO2 for enhanced photothermal ammonia catalysis

Ammonia (NH 3 ) is a hazardous pollutant that poses significant health and environmental risks, necessitating efficient removal strategies. Schottky junction-enhanced photothermal catalytic oxidation offers a promising approach to address the limitations of conventional photocatalysis, including low solar energy utilization and suboptimal catalytic performance. Here, metal nanoparticles (Ni, Pd, Pt, Cu, Ag) were loaded onto Mo-doped TiO 2 to construct Schottky junctions, resulting in significantly improved NH 3 oxidation performance. Notably, Pt uniquely outperformed other metals due to its exceptional stability in maintaining a metallic state even after prolonged exposure. In-situ DRIFTS analysis revealed a distinct ·NH 2 pathway for NH 3 oxidation on Pt/Mo-TiO 2 , differing from mechanisms observed in other metal-loaded catalysts. Combined experimental findings and DFT analyses provided direct evidence of the relationship between chemical states of metals, Schottky junction formation, and enhanced electron-hole separation. This study offers valuable theoretical insights into Schottky junction-enhanced photothermal catalysis and highlights its potential for efficient NH₃ removal under solar irradiation.