hydrous manganese dioxide nanoclusters are prepared by the oxidation of manganese (ii) ions with ammonium persulfate and used as a new sorbent for ag+ ion removal from aqueous medium. the synthesized compound is characterized using scanning electron microscopy, dynamic light scattering, energy dispersive analysis of x-rays, x-ray diffraction and bet surface measurements. scanning electron micro...

This research article deals with an electrosynthesis of hydrous titanium dioxide by anodic dissolution of titanium sacrificial anodes and their application for the adsorption of manganese from aqueous solution. Titanium sheet was used as the sacrificial anode and galvanized iron sheet was used as the cathode. The optimization of different experimental parameters like initial ion concentration, ...

Novel nanowall arrays of hydrous manganese dioxide MnO2 0.5H2O are deposited onto cathodic substrates by the potentiostatic method from a mixed aqueous solution of manganese acetate and sodium sulfate. The deposition is induced by a change of local pH resulting from electrolysis of H2O, and hierarchical mesoporous nanowall arrays are formed as a result of simultaneous precipitation of manganese...

A&met-Non-stoichiometric manganese dioxide prepared electrochemically at room temperature and suspended in dilute sulphuric acid is used to oxidise isosafrole to piperonal in 54% isolated yield. The manganese dioxide-manganese@) sulphate system can be recycled electrochemically at high current density. It has the further advantage that water-soluble materials derived from the chemical oxidation...

Several Mousterian sites in France have yielded large numbers of small black blocs. The usual interpretation is that these 'manganese oxides' were collected for their colouring properties and used in body decoration, potentially for symbolic expression. Neanderthals habitually used fire and if they needed black material for decoration, soot and charcoal were readily available, whereas obtaining...

-The sorption properties of Co, Cu, Ni, and Ca were studied in a mixed mineral suspension of synthetic MnO2 and Wyoming montmofillonite. The distribution of the sorbed cations between the two solid phases was measured by indirect chemical fractionation with acidified NH2OH-HC1 and by direct X-ray spectroscopic analysis of mineral particles using electron microscopy. Electron microscope and NH2O...