Fig. 1

Morphology and catalytic performance of FeNx. SEM images of FeN25 (a), FeN200 (b), and FeN300 (c). d OXD activity of three kinds of nanoparticles. e POD activity of nanoparticles. f POD activity of FeN200 in different time. g, h TA detection and statistical analysis of nanoparticles. i EPR detection of the generation of ·OH in different nanoparticles. The scale bar showed in Figure a-c indicated 500 nm. * indicated P < 0.05