Slice Visualization for Imaging Nanocluster Transformations

Metal nanoclusters have served as an emerging class of modular nanomaterials. Several efficient strategies have been proposed for transforming cluster precursors into new nanoclusters with customized structures and enhanced performance. However, such nanocluster transformations have still been in a blind box state, meaning that the existing intermediates were hard to track with atomic precision. Herein, we present a slice visualization approach for in-depth imaging of the nanocluster transformation from Au1Ag24(SR)(18) to Au1Ag30(SR)(20). With this approach, two cluster intermediates, namely, Au1Ag26(SR)(19) and Au1Ag28(SR)(20), were monitored with atomic precision. The four nanoclusters constituted a correlated Au1Ag24+2n (n = 0, 1, 2, and 3) cluster series with comparable structural features-the same Au1Ag12 icosahedral kernel but evolutionary peripheral motif structures. The mechanism of nanocluster structure growth was mapped in detail-insertion of Ag-2(SR)(1) or Ag-induced assembly of surface subunits. The presented slice visualization approach not only contributes an ideal cluster platform for in-depth investigations of structure-property correlations but also hopefully acts as a powerful means for obtaining clear information on nanocluster structure evolution.

Automated summary

Metal nanoclusters can be transformed into new nanoclusters with customized structures and enhanced performance using efficient strategies. However, tracking the nanocluster transformations has been challenging. In this study, a slice visualization approach was used to monitor the transformation of Au1Ag24(SR)(18) to Au1Ag30(SR)(20) nanoclusters. The mechanism of nanocluster structure growth was mapped and intermediate products were observed with atomic precision. This approach not only provides a platform for studying structure-property correlations but also offers a means to obtain clear information on nanocluster structure evolution.