Adsorption and catalysis of peroxymonosulfate on carbocatalysts for phenol degradation: The role of pyrrolic-nitrogen

Persulfate-based nonradical oxidation processes are appealing for removing refractory aromatic organic con-taminants in wastewater purification. Here, ultrathin nitrogen-doped carbonaceous catalysts with different pyrrolic-N contents were developed by a facile modifiable g-C3N4-templated strategy. We observed that N-C-6 has the highest pyrrolic-N content, and the presence of N-C-6 with Peroxymonosulfate (PMS) achieved almost 98 % degradation for phenol degradation within 30 min. Moreover, the decisive role of pyrrolic-N in activating PMS was illustrated through experiments, instrument characterization and theoretical calculations: the more pyrrolic-N-doping could exhibit the higher redox potential of the metastable complex with PMS, and the stronger interaction between both materials, the greater PMS adsorption, as a result, the oxidation rate of phenol is faster by charge abstraction reactions. The results provide a new strategy for the intrinsic roles of heteroatom doped carbon materials to activate persulfates.