Copper Hydr oxides

Properties Monodispersed, cubic particles, modal edge length 0.4 pm (pCu 3.2) to 1.6 pm (pCu 2.2) [1153], electron micrograph available [1154,1153], 

2 Natural, Origin Unknown, Water-Washed, and Dried at 110°C 

23 From Nitrate 0.2 M NaOH and 0.1 M CufNC),), solutions were simultaneously introduced with stirring into 100 cm of water at 10 cmVmin for 2 min at 20°C. This was then aged at 20°C for 5 d. 

2 Thermal Decomposition of Oxalate Oxalate was obtained from 1 M CufNO,), and a 10% excess of oxalic acid, washed with water, and calcined at 600°C, washed, and then calcined at 800-1400°C for 6 h. The oxide was washed with water until constant conductivity. 

Two recent papers report lEPs of CuO at pH 4 [3094] and 8 [3159]. Both values were obtained by arbitrary interpolation. 

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Pokrovsky OS, Viers J, Emnova EE, Kompantseva El, Freydier R (2008) Copper isotope fractionation during its interaction with soil and aquatic microorganisms and metal oxy(hydr)oxides possible structural control. Geochim Cosmochim Acta 72 1742-1757 Polyakov VB (1997) Equilibrium fractionation of the iron isotopes estimation from Mossbauer spectroscopy data. Geochim Cosmochim Acta 61 4213 217 Polyakov VB, Kharlashina NN (1994) Effect of pressure on equilibrium isotope fractionation. Geochim Cosmochim Acta 58 4739 750... 

Solubility data (pA sp) for two dozen hexacyanoferrate(II) and hexacyanoferrate(III) salts, and Pourbaix (pe/pH) diagrams for iron-cyanide-water, iron-sulfide-cyanide-(hydr)oxide, iron-arsenate-cyanide-(hydr)oxide, and iron-copper-cyanide-sulfide-(hydr)oxide, are given in a review ostensibly dedicated to hydrometallurgical extraction of gold and silver. " The electrochemistry of Prussian Blue and related complexes, in the form of thin films on electrodes, has been reviewed. ... 

The discharge of organic pollutants into lakes or declines in the concentrations of copper, zinc, and other heavy metal toxins may promote the growth of phytoplankton (e.g. algal blooms ). Greater biological activity may then increase anoxic conditions in lake bottoms, which stimulate the reductive dissolution of (oxy)(hydr)oxides and increase the mobilization of arsenic. In particular, Martin and Pedersen (2002) concluded that reduced discharges of copper, zinc, and nickel to Balmer Lake, Ontario, Canada, increased phytoplankton production and arsenic mobility in the lake. 

Hydrosilicate formation is also in evidence in the Cu(II)-Si02 system. Via precipitation from a homogeneous solution one can obtain highly dispersed copper oxide on silica (cf. above, Fig. 9.10, where it should be noted that the Cu case is more complicated than the Mn one in that intermediate precipitation of basic salts can occur). Reaction to copper hydrosilicate is evident from temperature-programmed reduction. As shown in Fig. 9.12 the freshly dried catalyst exhibits reduction in two peaks, one due to Cu(II) (hydr)oxide and the other, at higher temperature, to Cu(II) hydrosilicate. Reoxidation of the metallic copper particles leads to Cu(II) oxide, and subsequent reduction proceeds therefore in one step. The water resulting from the reduction of the oxide does not produce significant amounts of copper hydrosilicate, in contrast to what usually happens in the case of nickel. 

Copper group Copper oxides and hydr<side group Copper hydroxide Grice Gasparrini (1981) Scott (2002) 98... 

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