Activation of peroxymonopulfate by graphene-supported single-atom FeN5 with an ultra-low dose at low temperature: Nonradical mechanism and antibacterial activity

The catalytic activity of single-atom catalysts (SACs) is closely related to the coordination environment of metal center. Here, a new peroxymonosulfate (PMS) activation strategy based on graphitic carbon nitride-supported Fe SACs (FeCN) containing a five-coordinated structure (FeN5) exhibited remarkable catalytic performance towards doxorubicin hydrochloride (DOX) with an ultra-low-dose catalyst (10 mg center dot L-1) at a low temperature (4 degrees C). Singlet oxygen (O-1(2)) and high-valent iron-oxo species (HV-Fe)-dominated nonradical processes are responsible for the degradation and rapid inactivation of Escherichia coli (E. coil) and S. aureus. Density functional theory (DFT) calculations demonstrated that the terminal O of PMS adsorbed onto Fe-N-5 sites facilitated the subsequent homolysis of the O-O bond to genarate O-1(2) and HV-Fe. This work not only develops an efficient catalyst by finetuning the local coordination environment but also provides an insight into the mechanism of the nonradical-species-mediated PMS process as well as potential application at the device level.