Shape-Controlled Synthesis of Metal–Organic Frameworks with Adjustable Fenton-Like Catalytic Activity

Abstract

Controllable synthesis of metal–organic frameworks with well-defined morphology, composition, and size is of great importance toward understanding their structure–property relationship in various applications. Herein, we demonstrate a general strategy to modulate the relative growth rate of the secondary building units (SBUs) along different crystal facets for the synthesis of Fe–Co, Mn0.5Fe0.5–Co, and Mn–Co Prussian blue analogues (PBAs) with tunable morphologies. The same growth rate of SBUs along the {100}, {110}, and {111} surfaces at 0 °C results in the formation of spherical PBA particles, while the lowest growth rate of SBUs along the {100} surface resulting from the highest surface energy with increasing reaction temperature induces the formation of PBA cubes. Fenton reaction was used as the model reaction to probe the structure–catalytic activity relation for the as-synthesized catalysts. The cubic Fe–Co PBA was found to exhibit the best catalytic performance with reaction rate constant 6 times higher than that of the spherical counterpart. Via density functional theory calculations, the abundant enclosed {100} facets in cubic Fe–Co PBA were identified to have the highest surface energy and favor high Fenton reaction activity.

Insight into the Growth of Anisotropic CdSe Nanocrystals: Attachment of Intrinsically Different Building Blocks

“…A slab model in a vacuum box was employed to evaluate the surface energy of three low-index facets, namely the {100}, {111}, and {110} facets. Using a generalized gradient approximation functional, the slab geometry was optimized to a relaxed configuration, as shown in the top and side views of the {100}, {111}, and {110} surfaces in Figure a–f. − The surface energy was calculated based on the comparison of the relaxed slab geometry and bulk structure. As displayed in Figure k and Table , the calculated surface energy of the bare slab surface follows γ {110} < γ {111} < γ {100} , suggesting that the {100} surface is the most reactive one, while the {110} surface is the most inert.…”

Recent Improvement Strategies on Metal-Organic Frameworks as Adsorbent, Catalyst, and Membrane for Wastewater Treatment

“…To further optimize the catalyst’s properties, such as to maximize the available adsorption surface area or to create a facile pathway for substrate transfer, a specific and ordered morphology may be employed. Liu et al employed controllable synthesis method to reliably define the morphology of Fe 3 [CO(CN) 6 ] 2 , a MOF belonging to the category of Fe-Co Prussian Blue Analogues (Fe-Co PBAs) [ 106 ]. The group relies on the principle that growth temperature is able to influence the secondary building units (SBUs)’s growth rate in different crystal directions.…”

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“…Metal organic framework materials, also known as coordination polymers, were a new type of organic porous materials. It was a multidimensional network crystal material formed by self-assembly of metal ions or metal clusters with organic ligands that contained O, S, N, and P, among others. − In 1995, Professor Yaghi used a solvothermal method to synthesize a structurally stable MOF material for the first time . Since then, the application of MOF materials in various fields has been explored.…”