The thermal stability mechanism of gold nanorods in aqueous solution

Gold nanorods were prepared by seed-mediated growth method and were kept inaqueous solution between 45 and 105 °C. It was found that the longitudinal absorption peak of the gold nanorods obviously moved to a shorter wavelength between 60 and 90 °Cand this blue shift phenomenon disappeared after aperiod of time. In this paper, based on the theories of the liquid-like shell, combining the rule that the metal Gibbs free energy changes with temperature, the heat induced deformed mechanism has been studied and especially why the gold nanorods can be stably kept in aqueous solution at high temperature has been analyzed.