1. College of New Energy and Environment, Jilin University, Changchun 130021, China; 

 Aiming to 2, 4??dichlorophenol (2, 4??DCP) pollution in aqueous environment, the authors pre? pared nitrogen?sulfur co?doped biochar (NSBC) with high?efficiency adsorption and catalytic performance by high temperature pyrolysis process using rice straw as biochar precursor and thiourea as diatomic dopant for activating peroxynitrite (PMS) degradation of 2, 4??DCP, and characterizing them. The results showed that the diatomic do? ping significantly increased the specific surface area, redox activity and active sites of the biochar materials, such as oxygen?containing functional groups and nitrogen and sulfur functional groups. Under optimal conditions, NSBC had an efficient catalytic capacity with 95.30% degradation of 2, 4 ??DCP within 5 minutes. The degradation rate constant of NSBC / PMS system (0.542 min - 1 ) was 2.7 times higher than that of BC / PMS system (0.197 min - 1 ). In addition, NSBC still had good catalytic performance over a wide pH range. Analysis of electron spin resonance and quenching experiments showed that 1O2 and ·O - 2 generated by activated PMS acted as the main reactive oxy?gen species (ROS) for the degradation process of 2, 4??DCP.