Light‐Induced Electron‐Rich Gold Directs Nitrate Reduction to Dinitrogen
Yuwei Diao, Guangyu Huang, Yaru Luo, Sai‐Fei Tian, Shuai Li, Liling Wei, Zehao Li, Zhong‐Kun Li, Jianghan Chen, Qiong Liu, Hui ChengABSTRACT
Electrocatalytic nitrate reduction reaction (NO 3 RR) provides a controllable route for nitrate conversion, while nitrate purification requires directing the reaction endpoint toward inert N 2 instead of soluble reactive nitrogen species. Here, we establish operating‐state electron enrichment as a design principle for directing NO 3 RR toward N 2 and construct a Cu‐induced electronically reconfigured Au (ER‐Au) interface that enters an electron‐rich state under illumination. Electrochemical in situ interfacial characterization and theoretical calculations show that this electron‐rich environment transforms *NO‐related intermediates from isolated adsorption states into N‐N coupling reactive configurations, selectively enabling the NO 3 − to N 2 branch. Consistent with this branch regulation mechanism, ER‐Au selectively converts NO 3 − to N 2 with 90.84% Faradaic efficiency at pH = 1, as confirmed by product analysis and isotope‐labeling experiments, and further maintains stable operation for 100 h under illuminated acidic NO 3 RR conditions. The high N 2 Faradaic efficiency shows competitive performance among representative NO 3 RR electrocatalysts reported in the literature, especially considering the challenge of directing nitrate reduction toward the inert N 2 endpoint. More broadly, these findings identify operating‐state electron enrichment as a key mechanism and design principle for endpoint‐selective NO 3 RR.