Dataset for Covalently Grafted Molecular RuBda Catalyst on Pristine and S-doped g C₃N₄ for Controlled Photocatalytic Ammonia Oxidation

Here we report the first hybrid system capable of photocatalytic ammonia oxidation (AO), consisting of a molecular ruthenium catalyst (RuBda; Bda = 2,2′ bipyridine 6,6′ dicarboxylate) covalently anchored onto graphitic carbon nitride (g C₃N₄, CN) and S-doped g C₃N₄ nanoparticles (10P, 50P). The resulting hybrid photocatalysts (CNRuBda, 10PRuBda, 50PRuBda) combine the light harvesting properties and robustness of C₃N₄ with the well-defined reactivity of Ru in the catalytic centre of the RuBda moiety. Covalent grafting via surface –NH₂ defects enables high Ru loadings (up to 5.5 wt%) while preserving the structural integrity of the C₃N₄ framework. Electrochemical studies show that immobilised RuBda retains its intrinsic AO activity, exhibiting a ~0.33 V (vs NHE) cathodic shift of catalytic onset and turnover frequencies up to 5.6 s⁻¹ (CNRuBda). Under Xe lamp irradiation, all hybrid catalysts oxidise NH₃ to N₂ and H⁺, with CNRuBda producing up to 9.09 µmol N₂ in 3 h, a TOF of 1.55 × 10⁻³ s⁻¹, and a cumulative TON of 44 over three cycles. Accompanying minor NO₂⁻ formation and background N₂ evolution highlight the intrinsic complexity of AO. Overall, this work establishes the first proof-of-concept molecularly functionalised C₃N₄ photocatalysts for selective AO, opening new opportunities for solar-driven ammonia valorisation.