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Adsorption and Nonlinear Optical Properties of Ascorbic Acid on Silver Clusters: Experimental and DFT Study
J Suvetha Rani1, U Reeta Felscia2, S W Noah Eastman3
1Thiagarajar College, Madurai, India.
None:
The interaction between ascorbic acid (AA) and a silver nanocluster (Ag3) is investigated through a combined experimental and theoretical approach. Density Functional Theory (DFT) calculations at the B3PW91/6-311++G(d,p) and LanL2DZ levels revealed that adsorption of AA on Ag3 induces structural reorganization accompanied by charge transfer from Ag3 to AA. The charge transfer is confirmed by molecular electrostatic potential (MEP), natural population analysis (NPA), Fukui function analysis, and natural bond orbital (NBO) calculations. The reduced band gap of AA-Ag3 indicates the interaction between AA and Ag3. Experimental UV-Vis, Fourier-transform infrared (FTIR), and Fourier-transform Raman (FTR) spectra supported the computational findings, revealing changes in electronic and vibrational modes upon adsorption. The first hyperpolarizability (β) of AA-Ag3 is calculated to be 21 times higher than that of pristine AA. Open-aperture Z-scan measurements validated the predicted nonlinear optical (NLO) response, demonstrating the potential of the AA-Ag3 molecular system for advanced NLO device applications.
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