Fig. 1

Morphology and characterization of PBNPs. A TEM image of PBNPs. Scale bar = 100 nm. B SEM micrograph of PBNPs. Scale bar = 200 nm. C High resolution transmission electron microscopy (HRTEM) image. Scale bar = 10 nm. D SAED of PBNPs. Scale bar = 10 nm. E − I Element mapping of PBNPs. Green: C, Blue: Fe, Red: N, Yellow: K, I: Merged. Scale bar = 200 nm. J XRD pattern of PBNPs. K FTIR spectroscopy. L UV–vis-NIR spectrum. M Survey XPS spectra, and N − P Element XPS spectra (carbon, nitrogen, and iron) of PBNPs