Regio-selective growth of plates on Au nanorods

Morphological control is extremely difficult during the second-stage growth on existing nanoparticles. Here, we show that it is possible to combine nanorod and nanoplate morphologies by using partially encapsulated polystyrene-block-poly(acrylic acid) shells as the mask. Au nanoplates were grown selec-tively from the exposed surface of the Au nanorod, with consistent orientation for each nanorod. As such, we achieve three levels of synthetic control simultaneously: 1) the polymer mask focuses the Au deposition onto a few sites, so that the nanoplates could extend out prominently; 2) the longitudinal extension of the nanorod could be shifted to the traverse growth of nanoplates by using iodide ions as the inhibitor; 3) the nanoplates grow from only one of the twin planes because of the dynamic competition via the depletion sphere mechanism. (c) 2023 Elsevier Ltd. All rights reserved.