Trifluoromethanesulfonic Acid Bath for Electrodeposition of PbO2 on Ti/SnO2-Sb Substrate: Effects of Bath Composition and Deposition Current Density

The preparation of Ti/SnO 2 -Sb/PbO 2 electrode by electrodeposition in trifluoromethanesulfonic acid (TfOH) bath was investigated. The composition of the PbO 2 films is dominated by β -phase, and the preferential orientation of β (3 0 1) plane as well as the enhanced crystalline refinement are observed with increasing both TfOH concentration in the bath and deposition current density. It is demonstrated that non-stoichiometric lead dioxide is deposited on the substrates in the TfOH baths. The electrocrystallization of PbO 2 from the TfOH bath follows the typical instantaneous nucleation mechanism. The PbO 2 electrodes deposited from the TfOH baths exhibit superior stability. The accelerated lifespan of the electrode deposited under the optimal conditions (0.5 M TfOH and 10 mA cm −2 ) reaches 129 h, 4.0 times that of the conventional nitrate bath. Furthermore, the PbO 2 anode exhibits the higher electrocatalytic activity for methyl orange removal relative to the electrode prepared in the nitrate bath, which is attributed to the larger active specific surface area.