RESUMEN
Surface enhanced Raman spectroscopy (SERS) of p-aminothiophenol (PATP) was investigated on ß-Bi2O3/Bi2O2CO3 nanoparticles, a novel bismuth based metal substrate with the lowest limit of detection of 1 mM. Unlike on noble metal surfaces where PATP gets converted to p,p'-dimercaptoazobenzene (DMAB) due to photocatalytic coupling, no such transformation of PATP was observed on ß-Bi2O3/Bi2O2CO3 nanoparticles. Density functional theory (DFT) calculations at the PW91PW91/LANL2DZ/6-311+G(d,p) level of theory supported the experimental results exceedingly well. Also, the charge transfer direction from PATP to ß-Bi2O3/Bi2O2CO3 nanoparticles was revealed by the projected density of states calculation.
RESUMEN
Endohedral fullerenes have evinced much interest from the fundamental and applications points of view. However, given the nature of the weak interaction between the guest species and the host cage in these confined systems, the interaction energy values obtained using various theoretical methods, and different basis sets vary over a wide range. For example, the reported interaction energy for the HF@C60 system ranges from -2.5â kcal/mol to -14.9â kcal/mol. In the present manuscript, we report reliable interaction energy values for different endohedral fullerenes (He@C60 , Ne@C60 , Ar@C60 , Kr@C60 , H2 @C60 , HF@C60 , H2 O@C60 , NH3 @C60 , CH4 @C60 , Li+ @C60 , Na+ @C60 , and K+ @C60 ) obtained using the domain-based local pair natural orbital coupled-cluster singles, doubles, and perturbative triples (DLPNO-CCSD(T)) method and the def2-TZVP basis set. We believe that these energy values could be considered as benchmark values, and the performance of other quantum chemical methods could be assessed accordingly. Local energy decomposition analysis within the DLPNO-CCSD(T) framework is used to estimate the electrostatic, exchange, and dispersion components of the interaction energy for some of the endohedral fullerenes.
RESUMEN
Exploring the potential of non-noble metal substrates for Surface-enhanced Raman spectroscopy (SERS) has attracted considerable interest in recent years. In this work, we prepared nanoplate ß-Bi2O3/Bi2O2CO3 heterostructure via calcination of Bi2O2CO3 precursor using a facile hydrothermal process and successfully demonstrated its use as a novel SERS substrate. The SERS sensitivity of substrate was performed by probing methyl orange (MO), rhodamine B (RhB), vitamin C (Vit. C), and melamine. The observed results show that the SERS signal is enhanced considerably by the adsorption of probe molecules on the surface of the Bismuth heterostructure SERS substrate.
