Nitrogen-doped Zn/Fe@PCN derived from metal-organic frameworks activating persulfate to efficiently degrade rhodamine B

The Zn/Fe@N-doped porous graphitic carbon catalyst (Zn/Fe@PCN) was successfully produced through one-step pyrolysis of g-C3N4 and Zn/Fe-MOF and was used for the activation of persulfate (PS) for the degradation of RhB. The Zn/Fe@PCN/PS system was able to degrade 95.92% of RhB in 30 min at a rate of 0.6453 min(-1) when RhB was concentrated at 50 mg L-1. The efficient degradation of RhB is primarily realized through the synergistic activation of PS by Zn, Fe, and N to produce reactive oxygen species O-1(2), O-center dot(2)-, (SO4-)-S-center dot, and (OH)-O-center dot. Zn-0/Fe-0 in Zn/Fe@PCN forms a galvanic cell with carbon to release electrons to join in the activation of PS. The doping of Zn not only provides sufficient electrons for the activation of PS but also promotes the effective reduction of Fe2+ and thus the Fe2+/Fe3+ cycle. The N doping accelerates the electron transfer during the reaction progress.