Voltage‐Modulated Untwist Deformations and Multispectral Optical Effects from Ion Intercalation into Chiral Ceramic Nanoparticles

Abstract

Reconfiguration of chiral ceramic nanostructures after ion intercalation should favor specific nanoscale twists leading to strong chiroptical effects. In this work, V2O3 nanoparticles are shown to have “built‐in” chiral distortions caused by binding of tartaric acid enantiomers to the nanoparticle surface. As evidenced by spectroscopy/microscopy techniques and calculations of nanoscale chirality measures, the intercalation of Zn2+ ions into the V2O3 lattice results in particle expansion, untwist deformations, and chirality reduction. Coherent deformations in the particle ensemble manifest as changes in sign and positions of circular polarization bands at ultraviolet, visible, mid‐infrared (IR), near‐IR (NIR), and IR wavelengths. The g‐factors observed for IR and NIR spectral diapasons are ≈100–400 times higher than those for previously reported dielectric, semiconductor, and plasmonic nanoparticles. Nanocomposite films layer‐by‐layer assembled (LBL) from V2O3 nanoparticles reveal cyclic‐voltage‐driven modulation of optical activity. Device prototypes for IR and NIR range problematic for liquid crystals and other organic materials are demonstrated. High optical activity, synthetic simplicity, sustainable processability, and environmental robustness of the chiral LBL nanocomposites provide a versatile platform for photonic devices. Similar reconfigurations of particle shapes are expected for multiple chiral ceramic nanostructures, leading to unique optical, electrical, and magnetic properties.

Tri-mode Responses to Reactive Oxygen Species In Vivo by Chiral Vanadium-Based Nanoparticles

“…Transmission electron microscopy (TEM) images showed that the chiral d/l -V 2 O 3 /VN NPs had sizes of about 2.12 ± 0.17 nm. High-resolution TEM images showed that the d/l -V 2 O 3 /VN NPs had a lattice spacing of about 0.21 nm, which is consistent with the (610) planes of monoclinic V 2 O 3 (Figures B and S1). The dynamic light scattering results for l -V 2 O 3 /VN confirmed the size of the NPs (Figure S2).…”

“…Fourier transform infrared (FTIR) spectroscopy (Figure S5) showed that the peaks associated with the −OH, C�O, and C−O vibrations in Tar were significantly shifted, indicating that Tar was bound to the V 2 O 3 /VN NPs. 54 The ζ potential values of the L-V 2 O 3 /VN NPs and D-V 2 O 3 /VN NPs in water were −29.1 and −31.2 mV, respectively (Figure S6). The CD spectrum of chiral V 2 O 3 /VN showed four strong peaks at 400, 523, 634, and 906 nm (Figure 1C).…”

“…The CD signal of the Tar ligand was at 220 nm (Figure S10), and the multipoint binding of the Tar enantiomers on the surface of the inorganic nucleus led to the "built-in" chiral distortion of the V 2 O 3 /VN NPs. 54 Chiral V 2 O 3 /VN NPs for ROS Detection. In the presence of ROS, the multiple valences of vanadium allow oxidation and reduction reactions to occur.…”

“…The strong band at 878 cm –1 in the Raman scattering spectrum of the l -V 2 O 3 /VN NPs (Figure S4) is attributed to the VO bond. Fourier transform infrared (FTIR) spectroscopy (Figure S5) showed that the peaks associated with the −OH, CO, and C–O vibrations in Tar were significantly shifted, indicating that Tar was bound to the V 2 O 3 /VN NPs . The ζ potential values of the l -V 2 O 3 /VN NPs and d -V 2 O 3 /VN NPs in water were −29.1 and −31.2 mV, respectively (Figure S6).…”

Near-Infrared Chiroptical Activity Titanium Dioxide Supraparticles with Circularly Polarized Light Induced Antibacterial Activity

“…The surface chiral modification of nanomaterials provides an alternative approach to tune the band gap. ,,− Previous research has shown that chiral nanomaterials often exhibit unique light–electron interaction behavior, resulting in a CD intensity of 0 mdeg at the band gap edge of the material and strong CD signals at weak valence electron transitions − due to the Cotton effect, − the multiple exciton coupling effect, the long-range hyperconjugation effect, , van der Waals interactions, and the scattering effect . Consequently, this brings about significant changes in the photocatalytic reaction of TiO 2 and highlights the importance of preparing chiral TiO 2 with a CD signal in the NIR; using this strategy, it is possible to use circularly polarized light (CPL) to excite a catalyst, , thus providing another way for advancements in this field.…”