Carbon defects in biochar facilitated nitrogen doping: The significant role of pyridinic nitrogen in peroxymonosulfate activation and ciprofloxacin degradation

Heteroatom-Doped Hierarchically Porous Biochar for Supercapacitor Application and Phenol Pollutant Remediation

“…In addition, the mediator role of BC-24 and the electron-donating characteristic of hydroxyl groups enhanced the electron-transfer process from phenol to PDS, thus resulting in the oxidation of the phenol due to the high redox potential of the BC-24/PDS complex [ 52 ]. Moreover, the important active sites of the ketonic/carbonyl groups (C=O) [ 37 ] as well as the improved electric conductivity through doping of graphitic N, promoted the generation of 1 O 2 [ 29 ], thus resulting in the degradation of phenol. Meanwhile, the C=O/O–C=O functional groups at the defective edges can act as Lewis basic sites for PDS activation to generate free radicals of SO 4 · − and ·OH, thereby contributing to the radical pathway for phenol remediation [ 34 , 38 , 43 , 44 ].…”

“…Recently, persulfate-based advanced oxidation processes (AOPs) have emerged as promising technologies for the effective elimination of recalcitrant organic contaminants in wastewater, owing to the generation of powerful reactive oxygen species (ROS) including sulfate radical (SO 4 · − ), hydroxyl radical (·OH), superoxide radical (O 2 − ), and singlet oxygen ( 1 O 2 ) [ 25 , 26 , 27 ]. In comparison with the conventional AOP of Fenton reactions, persulfate-based AOP has a higher oxidation potential (2.5–3.1 V for SO 4 · − vs. 1.8–2.7 V for ·OH), longer lifespan (t 1/2 = 30–40 μs vs. t 1/2 < 1 μs), and wider pH range applicability (pH = 2−8 vs. pH = 3) [ 28 , 29 ]. Nevertheless, persulfate (PS) relies on an activation process to obtain high oxidation capacity, such as thermal activation, UV irradiation, ultrasonication, carbon-based or metal/metal oxide activation [ 26 , 27 , 28 ].…”

“…Nevertheless, persulfate (PS) relies on an activation process to obtain high oxidation capacity, such as thermal activation, UV irradiation, ultrasonication, carbon-based or metal/metal oxide activation [ 26 , 27 , 28 ]. Among these methods, the carbon-based activation systems have shown greater potential because of their advantages of strong adsorption capability, abundant surface functional groups, good electronic conductivity, and being free of secondary pollution [ 29 , 30 ]. Thereinto, biochar catalysts prepared from biomass waste with a hierarchically porous structure and doped, abundant heteroatoms have attracted tremendous attention.…”

“…As reported, nitrogen functionality can reconstruct the electron distribution of the neighboring carbon atoms thereby promoting catalytic activity toward PS activation by enhancing electron transfer ability [ 31 , 36 ]. In general, graphitic N can improve electrical conductivity and accelerate decomposition of PDS, leading to the generation of 1 O 2 and facilitating electron transfer; while pyridinic N can serve as an electron donor to organic pollutants and capture PDS molecules with high electrophilic characteristics [ 29 ]. Meanwhile, the oxygen functional groups can not only tailor the reductivity of the carbon framework but also regulate the zeta potential of the carbon surface, thereby affecting the interaction with the negatively charged persulfate ions [ 34 ].…”

Peroxymonosulphate Activation by Basolite® F-300 for Escherichia coli Disinfection and Antipyrine Degradation

“…To improve this technology, the use of a heterogeneous catalyst is recommended due to the fact that it is easier to recover and reduce the catalysts consumption. Several heterogeneous catalysts such as clays [ 43 ], biochar [ 44 ], or hydrochar [ 45 ] have tested in AOPs. In this context, recent studies reported the properties of MOF as novel categories of porous and well-crystallined material constructed from metal cations (or clusters of metal cations) which are linked to one another by bridging organic linkers [ 46 ].…”