Highly efficient conversion of nitrogen to ammonia on Au-decorated bioinspired polythiocyanuric acid photocatalyst

Abstract

Seeking low-cost and efficient method to convert nitrogen into ammonia under mild conditions is of great significance to modern agriculture and industry. Herein, a novel bioinspired polymer photocatalyst, polythiocyanuric acid ((C3N3S3)n) constructed by s-triazines bridged by disulfide bonds, the pivotal light-capturing component in the natural algae, is synthesized, whereby the s-triazine units serve as electron acceptor, and the disulfide bridges deliver strong electron transport capacity, and thus such a sulfur-rich polymer can not only effectively harvest sunlight, but also deliver efficient photogenerated charge transport. Consequently, the resultant (C3N3S3)n displays highly efficient N2 photofixation activity under UV-Vis or visible light illumination. With the aid of Au nanoparticles, the polymer achieves a UV-Vis-light-driven NH3 yield up to 366 μmol h−1 g−1 with an ultrahigh apparent quantum efficiency (14.6%) at 420 nm. The present results provide important guidance for the development of stable and efficient bioinspired polymer photocatalysts for artificial N2 fixation under mild conditions.