Fig. 1

Characterization of Bi:Cu₂O@HA NPs. A XRD pattern (red line). B SEM image. C TEM image and elemental mapping images. D FT-IR spectrum (red line). E DLS size distribution of the prepared Bi:Cu₂O@HA NPs. The blue lines in A are the diffraction peaks of cubic Cu₂O (JCPDS card NO:77–0199). The blue line in D is the FT-IR spectrum of HA