Formation of Highly Crystallized β‐PbO Thin Films by Cathodic Electrodeposition of Pb and Its Rapid Oxidation in Air

Abstract

The process of electrodeposition of β‐PbO thin films from aqueous solutions of PbII salts has been studied in detail. Contrary to the mechanism assumed in previous studies, thin films of crystalline β‐PbO are obtained after cathodic electrolysis in aqueous solutions of various soluble salts of PbII (Pb(NO3)2, Pb(ClO4)2, and Pb(CH3COO)2), and in both the presence and the absence of O2, thus indicating no contribution of OH– generation by electroreduction of NO3– and/or O2 to the formation of β‐PbO. A gradual color change is noted: a freshly electrodeposited gray film turns yellow as it dries in air. Drying of the films under controlled atmosphere (Ar or O2), combined with scanning electron microscopy (SEM) observation and X‐ray diffraction (XRD) measurement, has revealed that freshly deposited films are of metallic Pb, which are oxidized and converted into β‐PbO. Such a reaction is operative only when a freshly electrodeposited activated wet Pb film is in contact with gaseous O2. Despite the rapid conversion of a solid material, the resultant β‐PbO thin films are highly crystallized and possess highly ordered internal nanostructure. Elongated nanoparticles (30 nm × 100 nm) are assembled in a regular alignment to compose a large platelet (greater than 10 μm in size) with single‐crystalline character, as revealed by transmission electron microscopy (TEM) observation and selected‐area electron diffraction (SAED) measurement.

Direct deposition of inorganic–organic hybrid semiconductors and their template-assisted microstructures

“…Electrochemical deposition is from a three-electrode method using platinum mesh as the counter electrode and saturated calomel electrode (SCE) as reference electrode. Electrochemical deposition of PbO is carried out with the aqueous solutions of acetates 0.1 M Pb(CH 3 COO) 2 and 0.1 M CH 3 COONa at pH 4.0 onto conducting ITO glass substrates [37,38]. During the potentiostatic deposition, a potential of 1.2 V vs. SCE at room-temperature is used to obtain desired PbO thin films.…”

Formic Acid from Carbon Dioxide on Nanolayered Electrocatalyst

“…Due to mechanistic origin of those described above, Sawatani et al [14] suggested water removal from the cathodically electrodeposited Pb electrode by blowing hot air to preserve Pb under non-oxidized condition.…”

“…Pb acetate (Pb(CH 3 COO) 2 , 99 wt.%, Junsei) and perchlorate (Pb(ClO 4 ) 2 ·3H 2 O, ≥99.995 wt.%, Aldrich), whose anions are considered electrochemically inert unlike nitrate ion [14], were employed for Pb electrodeposition. Pb perchlorate was selected as a proper precursor since lead acetate leads to the formation of lead oxide acetate [15], one of the impurities on electrode when dried under air at room temperature.…”

Electrochemical Synthesis of PbO2, Pb3O4 and PbO Films on a Transparent Conducting Substrate

“…To circumvent this issue it is necessary to have an evaporation system solely for the purpose of lead-based material synthesis, this approach however is certainly not a cost-effective one. Whilst the electrochemical preparation of PbO 2 has been thoroughly studied [7], very little work has been undertaken on the electrochemical synthesis of PbO films [17,18]. In this report we present a novel, low-cost method for the synthesis of PbO and Pb 3 O 4 films on transparent conducting substrates by electroplating films of PbO 2 and then annealing in an air.…”