Enhanced ternary composite system Potassium-Cucurbit[6]uril-Ruthenium metal-support interactions in a heterogeneous system to facilitate photocatalytic nitrogen activation

The K-Ru/Q[6] catalyst, a ternary composite of Potassium, Cucurbit[6]uril, and Ruthenium, was developed to boost photocatalytic nitrogen reduction. It showed significantly higher activity for ammonia synthesis than Q[6] alone. Incorporating potassium increased the ammonia production rate to 12.5 μmol g⁻¹‧h⁻¹, a 2.3 times improvement over Ru/Q[6]. This enhancement is due to potassium ions strengthening the metal-support interaction (MSI) between Ru and Q[6], reducing electron-hole recombination and improving charge transfer. Characterizations using XPS, PL, EIS, UV-Vis DRS, and H₂-TPR revealed that potassium ions enhance electron mobility and lower the band gap. This study introduces a new photocatalyst for ammonia synthesis and offers insights into modulating catalytic activity via MSI.