Synthesis of bimetallic MOFs via interface control using gallium-based liquid metal

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) are versatile porous materials with tunable compositions for diverse applications.
• Conventional MOF synthesis methods face limitations such as high temperatures, long reaction times, and single-metal sourcing.
• Active metal incorporation, like Magnesium (Mg), is challenging due to passivation layer formation in electrochemical methods.

Purpose of the Study:

• To develop a novel electrochemical strategy for synthesizing bimetallic MOFs.
• To overcome the single-metal limitation in electrochemical anodic dissolution.
• To explore the application of synthesized MOFs in ultraviolet (UV) photodetection.

Main Methods:

• Utilized a liquid metal interface-controlled electrochemical strategy with a fluid Mg-Ga alloy anode.
• Employed electrocapillarity and Marangoni flow induced by the liquid gallium anode for dynamic metal ion release.
• Co-assembled Mg²⁺ and Zn²⁺ ions to form bimetallic ZnMg-MOF-74 under an optimized bias of 0.3 V.
• Derived ZnMgO oxide from the MOF via a two-step annealing process.

Main Results:

• Achieved dynamic and spatially uniform release of Mg²⁺ ions from a liquid metal anode.
• Synthesized highly crystalline ZnMg-MOF-74 with nanosheet morphology and uniform metal distribution.
• The derived ZnMgO oxide exhibited excellent UV photodetection performance with high responsivity (1.48 A/W) and fast rise time (0.32 s).

Conclusions:

• Introduced a substrate-free, composition-controllable platform for interface-driven synthesis of multimetallic MOFs.
• Demonstrated the potential of liquid metal electrochemistry for creating advanced MOF materials.
• Highlighted the utility of these MOFs and their derivatives in sensing and optoelectronic applications, particularly UV photodetection.