Optimization of Sample Preparation for Transmission Electron Microscopy Based on Several Nanomaterial Cases

Transmission electron microscopy (TEM) is an essential technique for characterizing nanomaterials. However, specimen preparation, which is a critical factor affecting image quality, remains a practical challenge. Focusing on nanopowders used in materials and chemical science, this article employs case studies to analyze the key steps in TEM specimen preparation. Carbon support films (CSFs) are essential tools for specimen preparation, and this study introduces several commonly used, cost-effective options, including conventional CSFs, conventional holey CSFs, ultrathin holey CSFs, and double-grid support films. We characterize their structural and morphological characteristics and evaluate their suitability for different types of samples. Several representative case studies of nanopowders, spanning from zero-dimensional (0D) to one-dimensional (1D) and two-dimensional (2D) materials, are used to illustrate tailored specimen preparation approaches, which serve as practical references for researchers conducting TEM characterization. These findings facilitate higher image reliability and experimental efficiency, thereby providing critical support for advancing fundamental exploration and frontier innovation in nanomaterial science.