(Cu(NO3)2·3H2O, AR grade), nickel
nitrate hexahydrate (Ni(NO3)2·6H2O, AR grade), iron nitrate nonahydrate (Fe(NO3)3·9H2O, AR grade), lanthanum nitrate hexahydrate (La(NO3)3·6H2O, AR grade), hydrogen peroxide
(H2O2, 30%, w/w), p-benzoquinone
(C6H4O2, CP grade), tert-butanol (C4H10O, CP grade), and sodium azide
(NaN3, AR grade) were obtained from Sinopharm Chemical
Reagent Co., Ltd (China). Florfenicol (C12H14Cl2FNO4S, 98%) were purchased from Adamas Reagent.
5,5-Dimethyl-1-pyrroline N-oxide (DMPO, C6H11NO, for ESR-spectroscopy) was purchased from Sigma-Aldrich
(St. Louis). Dimethyl sulfoxide (DMSO, C2H6SO,
99.8%) and 4-amino-2,2,6,6-tetramethylpiperidine (TEMP, C9H20N2, 98%) were purchased from Aladdin. All
required concentrations of the experimental solutions were diluted
with ultrapure water produced from a Milli-Q device (18.2 MΩ
cm at 25 °C).