Exfoliated Nanosheet Crystallite of Cesium Tungstate with 2D Pyrochlore Structure: Synthesis, Characterization, and Photochromic Properties
Citations Over TimeTop 10% of 2008 papers
Abstract
Layered cesium tungstate, Cs(6+x)W(11)O(36), with two-dimensional (2D) pyrochlore structure was exfoliated into colloidal unilamellar sheets through a soft-chemical process. Interlayer Cs ions were replaced with protons by acid exchange, and quaternary ammonium ions were subsequently intercalated under optimized conditions. X-ray diffraction (XRD) measurements on gluelike sediment recovered from the colloidal suspension by centrifugation showed a broad pattern of a pronounced wavy profile, which closely matched the square of calculated structure factor for the single host layer. This indicates the total delamination of the layered tungstate into nanosheets of Cs(4)W(11)O(36)(2-). Microscopic observations by transmission electron microscopy and atomic force microscopy clearly revealed the formation of unilamellar crystallites with a very high 2D anisotropy, a thickness of only approximately 2 nm versus lateral size up to several micrometers. In-plane XRD analysis confirmed that the 2D pyrochlore structure was retained. The colloidal cesium tungstate nanosheet showed strong absorption of UV light with sharp onset, suggesting a semiconducting nature. Analysis of the absorption profile provided 3.6 eV as indirect band gap energy, which is 0.8 eV larger than that of the bulk layered precursor, probably due to size quantization. The nanosheet exhibited highly efficient photochromic properties, showing reversible color change upon UV irradiation.
Related Papers
- → Synthesis of MoS2 nanosheet–graphene nanosheet hybrid materials for stable lithium storage(2013)304 cited
- → Enhanced fast response to Hg0 by adsorption-induced electronic structure evolution of Ti2C nanosheet(2021)42 cited
- → Zn-decorated S,P,B co-doped C2N nanosheet for ibuprofen adsorption: Experimental and density functional theory calculation(2023)19 cited
- → Density functional theory study towards capability of Ga-doped boron nitride nanosheet as a nanocarrier for 3-allyl-2 selenohydantoin anticancer drug delivery(2020)18 cited
- → Sensing Characterization of Metformin Drug by Pristine and Decorated BC3 Nanosheet: Quantum Chemical Study(2021)1 cited