Synthesis of Stable Aluminum Nanoparticles at Varying Reactant Concentrations and Their Surface-Enhanced Raman...

Area of Science:

• Nanomaterials Science
• Spectroscopy
• Chemical Engineering

Background:

• Aluminum nanoparticles (Al NPs) offer unique optical properties for sensing applications.
• Surface-enhanced Raman spectroscopy (SERS) typically utilizes gold or silver nanoparticles in the visible spectrum.
• Investigating Al NPs for UV-excited SERS, particularly for chemical warfare agent (CWA) surrogates, remains underexplored.

Purpose of the Study:

• To synthesize Al NPs using a scalable method with varying dilution factors.
• To characterize the synthesized Al NPs' properties, including yield, size, composition, and morphology.
• To evaluate the SERS performance of Al NPs as substrates for CWA surrogates under UV excitation.

Main Methods:

• Catalyzed thermal reduction of an aluminum precursor in anhydrous toluene with a capping ligand.
• Systematic variation of toluene volume to control dilution factors during synthesis.
• Characterization using techniques to determine yield, size distribution, chemical composition, and morphology.
• SERS analysis of Rhodamine 6G (R6G) and dimethyl methylphosphonate (DMMP) using 248.6 nm UV excitation.

Main Results:

• Consistent and favorable Al NP yields were achieved across all dilution factors.
• Characterization confirmed the formation of Al NPs with varying properties based on synthesis conditions.
• Modest SERS activity was observed for both R6G and DMMP using Al NPs with UV excitation.

Conclusions:

• The synthesis method is scalable and amenable to controlling Al NP properties.
• Al NPs demonstrate potential as low-cost SERS substrates for UV excitation.
• Further optimization is needed to enhance sensitivity for practical trace CWA detection applications.