Supramolecular colorless copper(I)–thiourea hydrogel (Cu-TU gel) has been made a mechanically strong functional hybrid material in the graphene oxide (GO) framework. Mild heat treatment (85 °C) of the hybrid material fetches black product containing hierarchical copper sulfide decorated reduced graphene oxide nanosheets (CuS-rGO) through an obvious in-house redox transformation reaction between Cu(I) and GO without any additive. The as-synthesized CuS-rGO nanocomposite exhibits impressive peroxidase-like activity where oxidation of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue product is observed in solution phase with H2O2. Systematic control experiments suggest that strong covalent interaction between CuS and rGO synergistically enhances the catalytic activity of CuS-rGO in comparison to its individual counterparts. Furthermore, an important biomolecule, dopamine, has been found to selectively inhibit, in succession, the oxidizing action of H2O2 for TMB oxidation reaction. Thus, dopamine-depend...

A Gel-Based Approach To Design Hierarchical CuS Decorated Reduced Graphene Oxide Nanosheets for Enhanced Peroxidase-like Activity Leading to Colorimetric Detection of Dopamine

Covellite copper sulfide submicron crystals in the shapes of ball-like, rodlike, and chrysanthemum-like architectures congregated from nanoslices with thickness of 20 to 100 nm have been prepared by a hydrothermal method without using any surfactant and characterized by X-ray diffraction, energy-dispersive X-ray spectrometer (EDX), UV−vis optical absorption spectra, and electron-microscopy techniques. A systematic investigation has been carried out to understand the factors influencing the evolution of the crystal morphology which was found to be predominant by the reactant molar ratio (Tu:Cu(NO3)2, Tu = thiourea), the hydrothermal reaction time, and the temperature. Possible crystal growth processes are also discussed.

Formation of various morphologies of covellite copper sulfide submicron crystals by a hydrothermal method without surfactant

The complex [Cu4(tu)7](SO4)2·H2O was isolated by addition of thiourea to a copper(II) sulfate electrolyte solution consisting of 2 M H2SO4 and 0.7 M CuSO4. The crystal structure of this complex was solved by X-ray methods and highlighted a [Cu4(tu)7]4+ adamantane cluster. A copper(I)−thiourea cluster of this stoichiometry has not been previously reported. The X-ray structure is refined to residual R = 0.0447 for 4093 observed reflections. Crystals are orthorhombic, of space group Pbca, with Z = 8 in a cell of dimensions a = 10.414(3), b = 17.909(3), and c = 35.818(3) A. The copper atoms lie in a tetrahedral arrangement in which one of the copper atoms is four-coordinate, while the other three display trigonal planar coordination with Cu···Cu distances of 2.899(2)−2.967(2)A. The copper−thiourea clusters are interlinked by sulfate ions, which strongly interact with the thiourea ligands through hydrogen bonds. The infrared and Raman spectra of the title compound and of the related copper(I) thiourea complexe...

Crystal structure of cu4(tu)7(so4)2.h2o and vibrational spectroscopic studies of some copper(i) thiourea complexes

This paper considers the effect of thiourea concentration, temperature and current density on electrodeposited copper nodulation. Thiourea concentration was varied from 0 to 60 mg dm−3 in the range 30 to 60°C and at current densities of 21.5, 48.4, 75.3 and 129.2 mA cm−2. Thiourea was found to initiate nodulation and this effect was always associated with a large increase in overpotential i. e., >100 mV. This phenomenon occurred only when the applied current density was greater than a critical current densityi
c. The critical current density was found to be insensitive to potential over a range of about 100 mV. Also, it decreased nonlinearly but smoothly with increase in thiourea concentration at a given temperature and increased similarly with temperature at a given thiourea concentration. Galvanostatic experiments were carried out to study this phenomenon and a qualitative explanation is given based on potentiodynamic measurements and suppositions as to the possible chemical reactions taking place at the cathode surface based on evidence in the literature.

Nodulation of electrodeposited copper in the presence of thiourea

Several synthetic strategies using copper(I) starting materials or copper(II) compounds and an in situ sulfite reductant have been used to systematically explore the chemistry of copper(I) complexes with thiourea and substituted thiourea ligands. This has resulted in the discovery of several new complexes and methods for the bulk synthesis of some previously reported complexes that had been prepared adventitiously in small quantity. The new complexes are (tu = thiourea, dmtu = N,N′-dimethylthiourea, etu = ethylenethiourea): [I4Cu4(tu)6]·H2O, [Cu4(tu)10](NO3)·tu·3H2O, [BrCu(dmtu)3], [ICu(dmtu)3]2, [BrCu(etu)2]2, [ICu(etu)2], [ICu(etu)2]3. [I4Cu4(tu)6]·H2O has an adamantanoid structure, with four terminal iodide ligands and six doubly bridging tu ligands. In contrast to this, [Cu4(tu)10](NO3)·tu·3H2O contains a tetranuclear cluster in which four of the tu ligands are terminal and the other six are doubly bridging. [BrCu(dmtu)3] is a mononuclear complex with tetrahedral coordination of copper by one bromide ...

A. Szymaszek

Papers

Polarographic studies on the effect of thiourea on deposition of copper in the presence of 2M H2SO4

Polarographic studies of the effect of halide ions on the copper electrodeposition process from 2m H2SO4 solutions containing other inhibitors

Polarographic investigation on influence of gelatine and casein on copper deposition.

Polarographic studies on the effect of thiourea on deposition of copper in the presence of 2m sulfuric acid

Polarographic and spectral studies of copper(I) oxidation in Cu(II)-thiourea-aminoacid-2M H2SO4 systems