Photoelectro‐Synergistic Catalysis at Ti/TiO₂/PbO₂ Electrode and Its Application on Determination of Chemical Oxygen Demand

Abstract

In this paper, photoelectro-synergistic catalysis oxidation of organics in water on Ti/TiO 2 /PbO 2 electrode was investigated by the method of electrochemistry. Furthermore, the results were compared with those obtained from photocatalysis and electrocatalysis. The method proposed was applied to determine the chemical oxygen demand (COD) value, Ti/TiO 2 /PbO 2 electrode functioning as the work electrode during the process. It was shown that the method of photoelectro-synergistic catalysis had lower detection limit and wider linear range than the methods of electroassisted photocatalysis and electrocatalysis. The results obtained by the proposed method and conventional one were compared by carrying out the experiment on 8 wastewater samples. The correlation of the results using different methods was satisfactory and the relative bias was below AE 6.0%.

Electrodeposited lead dioxide coatings

“…The degradation efficiencies improved slightly with the TiO 2 content and with increase in potential. Jin et al 157 utilized the PbO 2 /TiO 2 composite electrode as an amperometric sensor to determine the chemical oxygen demand of waste waters. The method had a low detection limit and wide application range and the COD values compared well with determinations by a traditional method.…”

Progress in the studies of photoelectrochemical sensors

“…The charge transfer between the interface of TiO 2 nanoparticles and the organic pollutants could happen and the photocurrent could be observed after the TiO 2 nanoparticles were stabilized onto conductive substrates. By detecting this photocurrent, the chemical oxygen demand (COD) was determined [64][65][66] . The results obtained from its application in artificial wastewater analysis were in good agreement with those from the conventional dichromate method; meanwhile, this approach requires no hypertoxic reagents and less analysis time, indicating that it would be another appropriate method for COD determination in water assessment.…”

Formation and growth of PbO2 inside TiO2 nanotubes for environmental applications

“…This can be explained by the passive nature of the TiO 2 layer and because of the poor stability of the layer due to the low miscibility between TiO 2 (18.8 cm 3 mol −1 ) and PbO 2 (24.97 cm 3 mol −1 ). Nevertheless, deposition of PbO 2 on TiO 2 may be a good alternative to improve the photochemical properties of TiO 2 and to simultaneously take advantage of the electrocatalytic activity of PbO 2 , as has recently been suggested by Li et al [48] and Devilliers and Mahé [49].…”

“…However, mechanical resistance and adherence problems between the Ti and the PbO 2 coating were observed, and the introduction of metallic transition layers was required to overcome such interfacial difficulties [29,35,44,45]. Thus, a particular type of anodic material called "modified titanium electrodes" has been developed; among these stand Ti/TiO 2 /PbO 2 as dimensionally stable anodes (DSAs) [46][47][48][49]. The use of TiO 2 as a transition layer improves the corrosion resistance of Ti but not so the conductivity and other intermixed properties related to the PbO 2 deposit.…”