Design and development of low-cost, high-efficient, metal-free persulfate heterogeneous catalysts was a hot research topic. Herein, porous pie-like nitrogen-doped biochar (NBC) was prepared by one step high temperature pyrolysis of rape straw, urea and ZnCl2 mixture, and applied for peroxymonosulfate (PMS) activation toward sulfamethoxazole (SMX) degradation. Among these as-prepared catalysts, the NBC2.0 sample presented the best catalytic activity, with the 99.8 % SMX degradation efficiency in 5 mins and the 81.7 % total organic carbon (TOC) removal rate in 30 mins. Additionally, it could rea...