Fig. 2

Scanning electron microscopy images and element mapping images of the fabricated MnO₂ nanozyme-doped diatom microbubbler. a Scanning electron microscopy image of diatom microbubbler (magnification: 15,000 times, white scale bar = 5 μm). b Scanning electron microscopy image shows pores on the surface of the diatom microbubbler (magnification: 50,000 times, white scale bar = 2 μm). c Element mapping images showing a homogenous distribution of MnO₂ nanozyme sheets on the diatom microbubbler (black scale bar = 800 nm)