Au@AZO core@shell nanoparticles were obtained via a similar hydrothermal route for the synthesis of Au@ZnO core@shell nanoparticles. After the hydrothermal synthesis, however, the 20 ml of the product solution are centrifuged and the Au@Zn(OH)2 nanoparticles are redispersed in an equal volume of an aqueous aluminum nitrate solution, neutralized to a pH of 6.5 with NH4OH. The aluminum nitrate concentration is adjusted to correspond to the intended doping at.%, assuming a quantitative inclusion of Al 3+ ions in the Zn(OH)2 shells. The Au@Zn(OH)2 NPs are left infusing in the Al(NO3)3 solution for 30 min. The sample is then dried at 150 °C for 30 min before calcination in air at 500 °C for 2 h.