Abstract
Thermal treatment is generally a desirable process to improve the properties of nanomaterials, which however often leads to undesirable problems such as aggregation and shape deformation. Here, we overcome this challenge by developing a ligand-assisted calcination strategy for shape-preserved chemical transformation of nanostructures. While capping ligands are often thought to be effective in solution phase synthesis, we show that their presence during high-temperature calcination not only maintains the overall particle morphology but also offers the possibility of effective creation of controllable porosity in metal oxide nanostructures. We demonstrate a particularly elegant example of this strategy, which involves the chemical conversion of β-FeOOH ellipsoids into porous α-Fe2O3 and magnetic Fe3O4 ellipsoids with morphological preservation and excellent solution dispersity via stabilization with strong coordinating capping ligands. The ligand-assisted solid-state conversion strategy represents a general self-templating method for creating nanomaterials, as confirmed by its successful application to a wide range of morphologies (ellipsoids, rods, cubes, and plates) and compositions (hydroxides and metal-organic frameworks).
Original language | English |
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Pages (from-to) | 3271-3277 |
Number of pages | 7 |
Journal | Chemistry of Materials |
Volume | 32 |
Issue number | 7 |
DOIs | |
State | Published - Apr 14 2020 |
Externally published | Yes |
Funding
Y.Y. acknowledges the support from the U.S. National Science Foundation (CHE-1808788). B.L. thanks the fellowship support by the China Scholarship Council (CSC). Acknowledgment is also made to the Donors of the American Chemical Society Petroleum Research Fund (55904-ND10) for partial support of this research. This work is also supported by the National Key Research and Development Program of China (No. 2018YFA0703300). J.C. thanks the support from the National Natural Science Foundation of China (51901147) and China Postdoctoral Science Foundation (2019M651939). The authors also thank the Central Facility for Advanced Microscopy and Microanalysis at UCR for help with TEM analysis.