A controllable transformation in copper valence states and its applications

Abstract

The present study revealed a surprising valence transformation of copper (Cu) in the sintering process of mixtures of copper chloride dihydrate (CuCl(2)·2H(2)O) with β-cyclodextrin (β-CD) in ambient atmosphere. Such a transformation in Cu valence states can be modulated by changing the initial molar ratio (IMR) of CuCl(2)·2H(2)O to β-CD in the mixtures. Firstly, as the value of IMR decreased, the content of cuprous chloride (CuCl) decreased, while the content of cupric oxide (CuO) increased gradually. That is to say, there is an unambiguous IMR-dependence of the contents of CuCl and CuO formed. However, such a controllable valence transformation from Cu(II) to Cu(I) to Cu(II) did not happen in nitrogen atmosphere. Secondly, the in situ composite of CuCl and CuO produced a highly ordered structure of self-assembled nanowires, intertwined, with a diameter of 30 to 50 nm. Furthermore, electronic structural analysis provided direct evidence that the Cu-Cl and Cu-O bonds in this composite material were simultaneously impaired by self-assembled growth. Finally, we noticed that the photoluminescence property of CuCl was regulated through the formation of composites with CuO. In addition, this in situ composite synthesis technique was used to modify the magnetic property of CuO. Furthermore, the anomalous ferromagnetic behaviour of the CuO nanocrystal was observed and explained. In short, this work not only demonstrates a flexible and easily controllable valence transformation of Cu, but also provides a novel approach for constructing inorganic nanocomposite materials. We believe that the implications of these findings are important and make significant contributions to the development of inorganic chemistry and material science.

Hydroxypropyl-β-cyclodextrin as a versatile additive for the formation of metastable tetragonal zirconia exhibiting high thermal stability

“…A full description of the applications of b-CDs is given in numerous reviews and papers. [21][22][23][24][25][26] Here, the idea is to take advantage of their unique topologies (rigid structure, large number of hydroxyl groups and ability to form supramolecular adducts with inorganic metal salts) [27][28][29][30] to interact intimately with the metal precursor and control the structure of metal oxide crystallites upon calcination. The strategy has been examined with the synthesis of ZrO 2 , starting from zirconium oxychloride (ZrOCl 2 ?8H 2 O) and 2-hydroxypropyl-b-cyclodextrin (HP-b-CD) as the metal precursor and organic additive, respectively.…”

Increased Water Solubility of Molybdenum Trioxide Induced by <em>&beta;</em>-Cyclodextrin

“…The C 1s peak (284.8 eV) was used as the internal standard for binding-energy calibration. Solid-state cross polarization/magic angle spinning (CP/MAS) 13 C NMR spectra were recorded on a Bruker AV-400 NMR spectrometer equipped with a 4 mm standard bore CP/MAS probe head whose X channel was tuned to 100.62 MHz for 13 C. Samples were packed in the ZrO2 rotor closed with Kel-F cap and spun at 10 kHz. 1 H NMR data were obtained on a Bruker NMR spectrometer at 300 MHz using CDCl3 with 0.03% TMS as an external reference at 298 K. Ultraviolet-visible-near infrared (UV-Vis-NIR) absorption spectra were conducted on a Shimadzu DUV-3700 spectrophotometer.…”

“…In addition, the decrease of the binding energies of Mo 3d5/2 and 3d3/2 means an increase in electron density of the 3d inner-shell region of Mo(VI), suggesting that the Mo -O bonds in BGP relative to the mixture were enhanced. CP/MAS 13 Vol.29…”

“…Also, a large number of reports on the preparation of metal oxide nanoparticles are associated with the addition of β-CD. 13 Further, numerous studies have proved that β-CD plays a crucial role in achieving ideal size and shape of inorganic nanoparticles. 14 On the contrary, without β-CD, results were usually unsatisfactory.…”

Two fluorescent copper phosphonate complexes for sensing antibiotics, ketones and Fe3+ in water

“…It is speculated that the monovalent copper ion undergoes an oxidation reaction during the solvothermal process. [39] The proposed reaction chemical equation is shown in (1).…”