The imaging of the gold nanoisland samples on graphene and hBN were done on a Zeiss Sigma 500 SEM. All samples were imaged at accelerating voltages ≤1 kV, with an aperture size of 30μm. Imaging of the palladium samples on graphene and hBN were done on a JEOL 1200 EX II TEM. All samples were images at an accelerating voltage of 80 kV.
For the analysis of the SEM and TEM images, the raw image files were edited by Adobe Photoshop CC 2019 Software by increasing the contrast, and in the case of TEM images, converting pixels stemming from the islands to white and gaps were converted to black pixels. The edited SEM and TEM images were analyzed using a custom python code, which extensively used the mahotas computer vision and image processing library.79 An iteration of this code is available freely at (https://github.com/juramire1/SEM_TEM_Image_Analysis ). An overview of the analysis is given previous work.17 (link)
For the analysis of the SEM and TEM images, the raw image files were edited by Adobe Photoshop CC 2019 Software by increasing the contrast, and in the case of TEM images, converting pixels stemming from the islands to white and gaps were converted to black pixels. The edited SEM and TEM images were analyzed using a custom python code, which extensively used the mahotas computer vision and image processing library.79 An iteration of this code is available freely at (
