Construction of a Novel Hydrogen-Bond-Assisted Bisulfide\nNonmetallic Active Center for Solar Ammonia Fertilizer Production

Solar-driven\nphotocatalytic nitrogen reduction is a promising and\neffective way to produce NH<sub>3</sub> in a sustainable manner. The\nreaction product, ammonium-based nitrogen, can mimic biological nitrogen\nfixation for plant growth and replace the use of exogenous nitrogen\nfertilizers. To address the bottleneck of N<sub>2</sub> activation\nduring N<sub>2</sub> reduction, nitrogen fixation catalyst dithiosalicylic\nacid (DTSA) with a hydrogen-bond-assisted S–S nonmetallic active\ncenter was constructed by thiosalicylic acid in this study, which\nachieved an ammonia yield of 278.9 μmol/h/g<sub>cat.</sub>.The\ninnovative application of the catalytic product as a replacement fertilizer\nfor the growth of Chlorella resulted in a significant increase in\nthe concentration of Chlorella without yellowing of the algal filaments\ncompared to the blank control group, indicating an adequate supply\nand functioning of nitrogen fertilizers. Further mechanistic studies\nreveal an alternating reaction pathway for nitrogen at the S–S\nactive center. The energy barrier of the rate-determining step (RDS)\nis effectively reduced from 2.79 to 2.11 eV with the aid of intermolecular\nhydrogen bonding of DTSA. The catalyst is controllable in mass production\nand simple in synthesis, and the catalytic product is used in the\ncultivation of Chlorella as an opportunity for the development of\nNRR catalysts for solar nitrogen fertilizers. Furthermore, the proposed\nnovel active center provides a new idea and direction for the development\nof future catalysts.