Preparation Of High Stability Lead Dioxide Electrocatalytic Material And Its Application In Degradation Of Organic Pollutants

In this paper,PbO₂ electrodes were prepared by electrodeposition in sulfamic acid（NH2SO3H）and lead nitrate（Pb（NO3）2）baths.NH2SO3H could refine PbO₂ grain,and the surfactants sodium dodecyl sulfate（SDS）and Triton X-100 could improve the electrocrystallization environment of PbO₂,thus improving the stability of the electrode.The prepared PbO₂（SDS+Triton X-100）electrode was applied to two organic pollutants of methylparaben（MePB）and malachite green（MG）to study the electrocatalytic oxidation capacity of the electrode,and the conclusions were as follows:（1）The doping of surfactants SDS and Triton X-100 could improve the oxygen evolution overpotential and stability of PbO₂ electrode.The lifetime and the lead ion dissolution of PbO₂（SDS+Triton X-100）electrode were about 1.5 times and 16.6%that of the undoped PbO₂ electrode,respectively.The main reason was that the surfactants could change the preferred orientation of PbO₂ crystals,which made the low-index facet β（101）more easily exposed and the high-index facet β（211）less easily exposed,thus reducing the OER activity of the PbO₂ electrode.（2）The PbO₂（SDS+Triton X-100）electrode was used for electrocatalytic degradation of the endocrine disruptor wastewater simulated by MePB.The results showed that the PbO₂（SDS+Triton X-100）electrode had excellent electrocatalytic oxidation ability.After 3h degradation,the MePB removal and COD removal could reach 100%and 91.4%,respectively,while the energy consumption was only 3.42 kWh.m-3.The degradation pathway was mainly through hydrolysis,dehydroxylation,decarboxylation,and hydroxylation to degrade MePB into small molecular organic matter.（3）PbO₂（SDS+Triton X-100）electrode was used for electrocatalytic degradation of the dye wastewater simulated by MG.The results showed that PbO₂（SDS+Triton X-100）electrode also had excellent electrocatalytic oxidation ability for the dye wastewater.After 3h degradation,MG and COD could be completely degraded,and the energy consumption was only 1.01 kWh·m-3.The degradation of MG was mainly through the destruction of C=C double bonds,C=N double bonds and benzene ring to convert MG into small molecular organics,H2O and CO₂.Among them,the C=C double bond in the MG structure was easy to be destroyed,followed by the C=N double bond,and the benzene ring was more difficult to be destroyed.Therefore,the PbO₂（SDS+Triton X-100）electrode prepared under these conditions had not only high stability but also excellent electrocatalytic oxidation ability in the application of organic wastewater.