The preparation of lead dioxide for X‐ray diffraction studies

Abstract

Lead dioxide is the active constituent of the positive electrode in the lead‐acid battery. Both the α‐ and the β‐modifications are present in battery electrodes and X‐ray diffraction techniques must be used to differentiate the role of each in the reactions occurring in the lead‐acid battery system. Standard samples of the two forms of lead dioxide are necessary for this purpose, and samples prepared by various methods have been studied. Powder patterns of electrodeposited samples of both α‐ and β‐lead dioxide showed preferred orientation effects which could not be removed by grinding. Chemically prepared samples of the two forms were well crystallised and did not produce preferred orientation effects. α‐Lead dioxide prepared by the oxidation of yellow lead monoxide (using a fused mixture of sodium chlorate and sodium nitrate) and β‐lead dioxide prepared by hydrolysis of lead tetra‐acetate were chosen as standard samples for X‐ray studies and their diffraction patterns have been recorded. A mechanism of nucleation has been proposed for the formation of α‐lead dioxide in alkaline and neutral media, and the β‐form in acid media.

Low-Cost Nanostructured Electrocatalysts for Hydrogen Evolution in an Anion Exchange Membrane Lignin Electrolysis Cell

“…51 All diffraction peaks obtained from the PbO 2 nanoparticles can be indexed to the tetragonal phase of lead dioxide and are in agreement with previously reported results on pure β-PbO 2 standard in the literature. 52 XRD results also confirm that the MWNTs were successfully impregnated with PbO 2 nanoparticles showing two typical characterization peaks at 25.95 o and 32.05°corresponding to the C (002) and β (101), respectively. The high angular and sharp reflection peaks in the XRD pattern suggest the crystallized structure of the acid-treated MWNTs and β-PbO 2 nanoparticles.…”

Electrodeposited lead dioxide coatings

“…There can, however, be problems with the quantitative determination of the ratio of a-PbO 2 /b-PbO 2 phases due to a number of factors. 5,[18][19][20][21][22] Even so, Dodson 23 and Munichandraiah 24 proposed a method for estimating the relative amounts of a-PbO 2 and b-PbO 2 in mixtures of the two phases, which gave reproducible results within an error of 5%.…”

In situsynchrotron X-ray diffraction investigation of the evolution of a PbO2/PbSO4surface layer on a copper electrowinning Pb anode in a novel electrochemical flow cell

“…While both phases have been observed on the surface of Pb-based anodes (e.g. Bagshaw et al, 1966;Hill, 1982), -PbO 2 is metastable with respect to -PbO 2 under ambient conditions (White et al, 1961;White & Roy, 1964) and it is the -PbO 2 phase that forms more commonly. It is believed that different pH conditions will control the mechanism by which the PbO 2 crystals are formed (Fletcher & Matthews, 1981), and subsequently which structure forms.…”