Sci Rep. 2023 Jan 21;13(1):1212. doi: 10.1038/s41598-023-28470-x.
The replacement of metals in catalytic processes is highly demanded to improve sustainability and economic growth. Poor stability and metal leaching are the main drawbacks of metal-based catalytic reactions. This work represented the use of nitrogen and sulfur-co-doped mesoporous carbon material ((N, S)-MPC) as a metal-free catalyst for the degradation of 4-nitrophenol (4-NP) as a priority pollutant announced by the Environmental Protection Agency through the persulfate-based advanced oxidation process. A low amount of (N, S)-MPC catalyst (0.3 g/L) exhibited superior performance for the degradation of 4-NP within 3 h at room temperature and unadjusted pH. The COD removal was calculated to be 76% using (N, S)-MPC catalyst. Interestingly, the degradations kinetics of 4-NP followed the zero-order kinetics with the rate constant of 0.505 min-1. The radical quenching experiment was accomplished to investigate the activation pathway of degradation. A real sample from an oil and gas company was treated with the (N, S)-MPC catalyst, which showed excellent total decontamination of 61%. The recyclability and stability of the catalyst have been evaluated for three runs. Owing to the obvious benefits such as high efficiency, metal-free nature, and recyclability, the presented catalyst can improve pollutant removal from aqueous media and practical environmental remediation.