Stable and Efficient Selective Photochemical Conversion of Nitric Oxide into Nitrates via Earth‐Alkaline‐Carbonate‐Doped N‐Rich Carbon Nitride
Chaoyong Yang, Jialin Li, Junlei Zhang, Guojia Yu, Jingling Yang, Mingshan Zhu
Abstract
Abstract Achieving stable and selective photooxidation of NO x in air remains a significant challenge. Here, the study reports a doping strategy using alkaline‐earth carbonates to enhance the photocatalytic performance of N‐rich carbon nitride (C 3 N 5 ). The BaCO 3 ‐doped C 3 N 5 (BaCO 3 /C 3 N 5 ) composite demonstrates a remarkable NO removal efficiency of ≈60%, surpassing pristine BaCO 3 and N‐rich C 3 N 5 by factors of 60 and 12, respectively. This substantial enhancement is attributed to the synergistic effects of BaCO 3 doping, which promotes photogenerated carrier separation and transport, improves NO/O 2 adsorption and activation, and broadens visible‐light responsiveness. Notably, BaCO 3 /C 3 N 5 exhibits stable NO removal efficiency and high selectivity for nitrate (NO 3 ⁻ ) during ten consecutive cycles, as evidenced by in situ DRIFTS. Similarly, doping with CaCO 3 and SrCO 3 yields comparable improvements in performance. Furthermore, the NO removal efficiency per milligram of these composites and their effective suppression of toxic NO 2 intermediates surpass those of 36 reported C₃N x ‐based (X = 4, 5) and insulator‐based photocatalysts. This work provides valuable insights into the design of advanced photocatalysts for air pollution control, offering a sustainable pathway for mitigating NO x emissions.