Adsorption and Nonlinear Optical Properties of Ascorbic Acid on Silver Clusters: Experimental and DFT Study

Area of Science:

• Computational Chemistry
• Materials Science
• Nanotechnology

Background:

• Understanding molecular interactions is crucial for developing new materials.
• Silver nanoclusters offer unique electronic and optical properties.
• Ascorbic acid is a biologically relevant molecule with potential reducing capabilities.

Purpose of the Study:

• To investigate the interaction between ascorbic acid (AA) and a silver nanocluster (Ag3).
• To explore the resulting changes in electronic structure and optical properties.
• To assess the potential for nonlinear optical (NLO) applications.

Main Methods:

• Combined experimental (UV-Vis, FTIR, FTR, Z-scan) and theoretical (Density Functional Theory - DFT) approaches.
• DFT calculations included B3PW91/6-311++G(d,p) and LanL2DZ levels.
• Analysis techniques: Molecular Electrostatic Potential (MEP), Natural Population Analysis (NPA), Fukui function, Natural Bond Orbital (NBO).

Main Results:

• Adsorption of AA on Ag3 induced structural changes and charge transfer from Ag3 to AA.
• Reduced band gap in the AA-Ag3 system confirmed interaction.
• Experimental spectra (UV-Vis, FTIR, FTR) supported computational findings.
• First hyperpolarizability (β) of AA-Ag3 was 21 times higher than pristine AA.
• Z-scan measurements validated significant nonlinear optical (NLO) response.

Conclusions:

• The AA-Ag3 molecular system exhibits enhanced NLO properties due to strong interaction.
• This study demonstrates the potential of AA-Ag3 for advanced NLO device applications.
• The combined theoretical and experimental approach provides a comprehensive understanding of the interaction.