Chiral Inorganic Nanomaterials Characterized by Advanced TEM: A Qualitative and Quantitative Study

Chiral inorganic nanomaterials (CINMs) have garnered significant interest due to their exceptional optical, electronic, and catalytic properties, offering promising advancements in energy conversion, data storage, catalysis, and biomedicine. While traditional optical spectrophotometers reveal the chiroptical performance of CINMs on an ensemble level, the direct structural visualization for the qualitative and quantitative discernment of their chiral features has become increasingly distinct with the advancements of transmission electron microscopy (TEM) techniques. The need for reasonable and high-standard discrimination requirements of CINMs has driven the progress of chirality-based TEM technologies. Therefore, this review in the good season takes the initiative to summarize the current advancements in TEM technologies for CINMs characterization, emphasizing a qualitative analysis of chiral atomic-level features, 0D, 1D, and 2D nanocrystals, and assembled nanomaterials. Then, the quantitative methods for determining chirality is also highlighted, such as 3D electron tomography, and further address the evolution of chiral structures monitored by the Ex-situ and In-situ TEM technologies. By providing a roadmap for the current challenges and proposing future advancements in TEM technologies for the qualitative, quantitative, and real-time analysis of CINMs, it can drive innovations in the field of chiral nanomaterials as well as the development of TEM technologies.