Neglected roles of self-confined trace elements in biowaste-derived carbon in Fenton-like oxidation

Value-added utilization of biowastes has been a research hot spot in waste-to-resource field. However, the roles of the self-confined trace elements in biowaste-derived carbon have been frequently neglected. Herein, using mango seeds-derived carbon (MSC) as a proof of concept, the pivotal roles of self-confined trace elements in peroxymonosulfate (PMS) activation toward Rhodamine B (RhB) removal were rectified. The selected mesoporous MSC 1000 (carbonization at 1000 °C), with more than 10 trace elements (Ca, O, K, Mg, Si, Fe, Cu, etc.), had an ultrahigh BET specific surface area of 1903 m 2 /g. It presented outstanding adsorption capacity, which, in combination with remarkable activity for PMS activation, facilitated total RhB removal within 60 min. Quenching experiments, EPR tests and chemical probes collectively revealed that high-valent metal-oxo species, e.g., Fe(IV) O, generated from self-confined trace metal/metal oxides, dominated RhB mineralization. Furthermore, the secondary 1 O 2 was also produced at pyridinic N and graphite N active sites. In addition, MSC 1000 had prominent adaptability to complicated water matrices. Surprisingly, regeneration by recalcination can improve catalyst’s performances. This study help recognize the critical roles of trace components in carbonaceous catalysts in Fenton-like oxidation toward wastewater decontamination.