S-Doped Sb₂O₃ Nanorods for Electrocatalytic Nitrogen Reduction

Sulfur-doped Sb2O3 nanorods (X-Sb2O3) have been synthesized via a self-assembly process with subsequent calcination, using bulk Sb as the precursor and H2SO4 as the sulfur source. The obtained X-doped Sb2O3 nanorods were confirmed as efficient and stable catalysts for electrochemical nitrogen reduction, which exhibited a superior ammonia yield of 6.88 mu g h(-1) cm(-2) with a Faradaic efficiency of 32.5% at -0.18 V versus RHE. Moreover, the doping amount of sulfur in X-Sb2O3 could be controlled by the calcination temperatures in a muffle furnace. Density functional theory calculations revealed that N-2 was readily adsorbed on the O atom of the 300-Sb2O3 surface, and the subsequent reduction reactions further occurred on the O active site by the distal mechanism. Meanwhile, the superior electrocatalyst performance of 300-Sb2O3 was attributed to sulfur doping, which effectively tuned the electronic structures of Sb2O3 to promote the adsorption and activation ability of N-2. This work provides an easy and efficient way to dope non-metals in Sb2O3 for excellent electrocatalytic performance.