Sulfur Atomically Doped Bismuth Nanobelt Driven by Electrochemical Self-Reconstruction for Boosted Electrocatalysis

Recent years have witnessed various in-depth research efforts on self-reconstruction behavior toward electrocatalysis. Tracking the phase transformation and evolution of true active sites is of great significance for the development of self-reconstructed electrocatalysts. Here, the optimized atomic sulfur-doped bismuth nanobelt (S-Bi) is fabricated via an electrochemical self-reconstruction evolved from Bi₂S₃. Advanced technologies have demonstrated that the nonmetallic S atoms have been doped into the lattice Bi frame, leading to the reconstruction of local electronic structure of Bi. The as-prepared S-Bi nanobelt exhibits a remarkable NH₃ generation rate of 10.28 μg h^-1 mg^-1 and Faradaic efficiency of 10.48%. Density functional theory calculations prove that the S doping can significantly lower the energy barrier of the rate-determining step and enlarge the N≡N bond for further dissociation toward N₂ fixation. This work not only establishes insights into the evolution process of electrochemically derived self-reconstruction but also unravels the root of the N₂ reduction reaction mechanism associated with the atomic nonmetal dopants.