Concurrent Ammonia Synthesis and Alcohol Oxidation Boosted by Glutathione-Capped Quantum Dots under Visible Light.

Mother nature accomplishes efficient ammonia synthesis via cascade N ₂ oxidation by lightning strikes followed with enzyme-catalyzed nitrogen oxyanion (NO _x ^- , x = 2,3) reduction. The protein environment of enzymatic centers for NO _x ^- -to-NH ₄ ⁺ process greatly inspires the design of glutathione-capped (GSH) quantum dots (QDs) for ammonia synthesis under visible light (440 nm) in tandem with plasma-enabled N ₂ oxidation. Mechanistic studies reveal that GSH induces positive shift of surface charge to strengthen the interaction between NO _x ^- and QDs. Upon visible light irradiation of QDs, the balanced and rapid hole and electron transfer furnish GS·radicals for 2e ^- /2H ⁺ alcohol oxidation and H·for 8e ^- /10H ⁺ NO ₃ ^- -to-NH ₄ ⁺ reduction simultaneously. For the first time, mmol-scale ammonia synthesis is realized with apparent quantum yields of 5.45% ± 0.64%, and gram-scale synthesis of value-added acetophenone and NH ₄ Cl proceeds with 1:4 stoichiometry and stability, demonstrating promising multielectron and multiproton ammonia synthesis efficiency and sustainability with nature-inspired artificial photocatalysts.
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