Fig. 4: Crystal and morphology characterizations.

a XRD patterns of TiO₂ and Pd-HPP-TiO₂. The vertical lines are the position and intensity of anatase TiO₂ (JCPDS 21-1272) and Pd (labeled by the star, JCPDS 46-1043). b TEM, c, d HRTEM, e STEM, and f–i the corresponding EDX element mapping images of Pd-HPP-TiO₂.