Tuning excited-state electronic structure in tungsten oxide for enhanced nitrogen photooxidation as fertilizer.

Nitrate (NO 3 –) is an important raw ingredient for fertilizer, but its conventional synthesis is restricted by high energy consumption and CO 2 emissions. Though there have been some studies on photocatalytic nitrogen oxidation, the production rate of nitrate is undesirable and the excited-state charge-transfer pathway still remains unclear. Herein, we fabricated the V-doped W 18 O 49 nanowires (V- W 18 O 49) for direct nitrate synthesis from N 2 photooxidation. The NO 3 - production rate is as high as 39.85 μmol g−1 h−1 with exceptional catalytic stability and the photosynthetic nitrate fertilizer was employed to promote the growth of crops. Time-resolved spectroscopic results confirmed that the introduction of V doping in V- W 18 O 49 has created new high-efficiency electron-transfer (ET) pathways from the W-O site to the V-dopant under photoirradiation, which leads to an improved π-backdonation process that facilitates nitrogen activation. This newly formed ET channel facilitated efficient charge separation and ultrafast photogenerated carriers transfer, thus overcame the sluggish ET kinetics. [Display omitted] The V-doped W 18 O 49 nanowires were rationally designed and successfully fabricated through a facile solvothermal method. The NO 3 - production rate is as high as 39.85 μmol g−1 h−1 and the photosynthetic nitrate was employed as N-fertilizer. The introduction of V dopants created new high-efficiency electron-transfer (ET) pathways that facilitated the photogenerated carriers transfer. [ABSTRACT FROM AUTHOR]