Promoted photocatalytic N 2 fixation to ammonia over floatable TiO 2 /Bi/ Carbon cloth through relay pathway

The floatable photocatalyst at N 2 -water interface allows the adequate supply of N 2 reactant and the utilization of photothermal energy for photocatalytic N 2 fixation, however, the presence of non-volatile NO 3 - product poses a challenge to the stability as it easily covers the catalytic active sites. Herein, a floatable TiO 2 /Bi/CC (Carbon cloth) photocatalyst was designed, in which the non-volatile NO 3 - can be transformed to the volatile NH 3 via the newly synergistic relay photocatalysis pathway (N 2 -> NO 3 - -> NH 3 ) between TiO 2 (N 2 -> NO 3 - ) and Bi (NO 3 - -> NH 3 ). Attractively, the spontaneous NO 3 - -> NO 2 - step occurs on Bi component to promote the relay pathway performing. Therefore, TiO 2 /Bi/CC system displays better long-term stability than TiO 2 /CC, and moreover, it achieves a higher NH 3 yield of 8.28 mmol L -1 h -1 g -1 (i.e. 4.14 mmol h -1 m - 2 ) than that 1.46 mmol L -1 h -1 g -1 for TiO 2 /Bi powder. Importantly, the N 2 fixation products by TiO 2 /Bi/CC effectively promote lettuce growth and enhance lettuce nutrient contents, which further validates the feasibility of this system in large-scale application of crop cultivation.