Controlled synthesis of gold nano bipyramids

Gold nano bipyramids (Au NBPs) and nanorods (Au NRs) have been heavily researched due to their unique properties, but the current growth methods have shown to be too tedious. They are specialized gold nanoparticles with distinct shapes, and there are two common types of elongated colloidal plasmonic metal nanocrystals. The difference is that Au NPBs have narrower shapes and sharper tips than Au NRs. In this study, we utilizedthe seed-mediated approach to synthesize the Au NBPs sample and focus on improving the yield of Au NBPs and aim to understand the effect of the concentration ratio between CTAC/sodium citrate by changing the concentration of sodium citrate to obtain a high yield of Au NBP. We also tried various CTAB concentrations within our growth solution during our study. We kept most of our growth solution formula the same throughout this experiment but with varied concentrations of CTAB with the same seed solutions. We had to be precise with how much of each chemical we added to our solution and the order in which we added them. Preliminary results showed that the growth solution with 40mM of CTAB combined with the concentration CTAC/CiNa3 21:1 seed solution was better than the one with 50mM of CTAB. Each sample's characterization was measured using Transmission Electron Microscopy (TEM) and UV-Vis spectra. As we find ways to improve the meditated seed growth of Au NBPs, they have a high potential to be useful for future uses, such as in the photocatalyst and medical fields.