PbO2–CeO2 nanocomposite electrodes were prepared by pulse electrodeposition method in the lead nitrate solution containing CeO2 nanoparticles with different peak current density. The content of CeO2 nanoparticles in the electrodes increase with the increase of peak current density. The effects of peak current density on the morphology and structure of PbO2–CeO2 nanocomposite electrodes were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The SEM and XRD results show that the increase of peak current density can make the morphology finer and more compact, and the crystal size decreases with the increase of peak current density. The oxygen evolution overpotential and stability of PbO2–CeO2 nanocomposite electrodes enhance with the increase of peak current density. The electrocatalytic property of PbO2–CeO2 nanocomposite electrodes was examined for the electrochemical oxidation of rhodamine B (RhB). The results show that the RhB removal efficiency on PbO2–CeO2 nanocomposite electrodes increase with the increase of peak current density, which can be attributed to the higher oxygen evolution overpotential and CeO2 content in the composite electrodes.

Electrocatalytic oxidation is a promising process for degrading toxic and biorefractory organic pollutants in wastewater treatment. Selection of electrode materials is crucial for electrochemical oxidation process. In this study, Ti/F-PbO2 and Ti/Sb-SnO2 electrodes were chosen to compare their electrocatalytic characterization, which were prepared by electrodeposition and thermal decomposition method, respectively. The surface morphology and crystal structure of two electrodes were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The linear polarization curves show that Ti/Sb-SnO2 electrodes possess higher oxygen evolution overpotential than Ti/F-PbO2 electrodes. But the stability and corrosion resistance ability of Ti/F-PbO2 electrode was higher than that of Ti/Sb-SnO2 electrode. The electrocatalytic activity of Ti/F-PbO2 and Ti/Sb-SnO2 electrodes was examined for the electrochemical oxidation of malachite green (MG). The bulk electrolysis shows that the Ti/Sb-SnO2 electrodes exhibit the higher electrocatalytic activity for the degradation of MG than Ti/F-PbO2 electrodes, and the degradation process is good fitting for the pseudo-first order reaction. The higher electrocatalytic activity of Ti/Sb-SnO2 electrodes can be attributed to the higher oxygen evolution overpotential.

PbO2–ZrO2 composite electrodes were prepared by anodic electrodeposition in the lead nitrate solution. The electrochemical property of this electrode was studied by cyclic voltammetry, polarization curves and open-circuit potential–time curves. The results show that PbO2–ZrO2 composite electrodes possess higher oxygen evolution overpotential and better anti-corrosion performance than traditional PbO2 electrodes. Electrocatalytic oxidation of 4-chlorophenol (4-CPs) in aqueous solution was studied to evaluate the applications of this electrode in environmental protection. The influence of experimental parameters on the COD removal efficiency was studied on PbO2–ZrO2 composite electrodes as a function of the current density, initial concentration of the 4-CPs, initial pH, supporting electrolyte concentration and electrolysis time. The results show that the 4-CPs removal efficiency in 0.1 mol L–1 Na2SO4 solution containing 8 mmol L–1 4-CPs could reach 89.2% with the current density at 200 mA cm–2 and pH value at 6.5 after 4 h. Compared with traditional PbO2 anodes, the PbO2–ZrO2 composite electrodes show higher instantaneous current efficiency with degradation of 4-CPs. The experimental results demonstrate that the PbO2–ZrO2 composite electrodes possess the excellent electrocatalytic activity in refractory pollutants degradation.

Lead dioxide electrodes were prepared by pulse electrodeposition in the lead nitrate solution with different pulse current density. The effects of pulse current density on the morphology and structure of lead dioxide electrodes were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The SEM and XRD results show that the increase of pulse current density can make the morphology more fine, and the crystal size of lead dioxide decreases with the increase of pulse current density. The anodic polarization curves demonstrate that the oxygen evolution overpotentials of lead dioxide electrodes also enhance with the increase of pulse current density. The stability of lead dioxide electrodes enhances with the increase of pulse current density until 15 mA cm–2, then the stability decreases. The electrocatalytic property of lead dioxide electrodes was examined for the electrochemical oxidation of rhodamine B (RhB). The results show that the RhB removal efficiency on the lead dioxide electrodes increases with the increase of pulse current density, which can be attributed to the increase of oxygen evolution overpotential.

PbO2-CeO2 nanocomposite electrodes were prepared by pulse electrodeposition in the lead nitrate solution containing CeO2 nanoparticles with different duty cycles. The effects of duty cycle on the morphology and phase structure were investigated by scanning electronic microscopy (SEM) and X-ray diffraction (XRD), respectively. The SEM and XRD results show that the decrease of duty cycle can reduce the grain size of PbO2-CeO2 nanocomposite electrodes and make the electrodes more compact. The CeO2 content in composite electrodes increases with the decrease of duty cycle. The steady-state polarization curves and accelerated life tests demonstrate that the oxygen evolution overpotential and service life of PbO2-CeO2 nanocomposite electrodes increase with the decrease of duty cycle. The service life of PbO2-CeO2 nanocomposite electrodes prepared with 25 % duty cycle reaches 218 h which is 1.8 times longer than that of PbO2-CeO2 nanocomposite electrodes prepared by direct electrodeposition. The bulk electrolysis shows that the degradation of malachite green (MG) on the PbO2-CeO2 nanocomposite electrodes is the pseudo-first-order reaction and the MG and chemical oxygen demand (COD) removal efficiency on PbO2-CeO2 nanocomposite electrodes increases with the decrease of duty cycle, which can be attributed to the higher oxygen evolution overpotentials, electrochemical active surface area, and CeO2 content in the composite electrodes.

PbO2-ZrO2 nanocomposite electrodes were prepared by pulse electrodeposition in the lead nitrate plating bath containing ZrO2 nanoparticles. The effect of pulse electrodeposition parameters, such as pulse frequency, average current density and duty cycle, on the ZrO2 weight percentage in the PbO2-ZrO2 nanocomposite electrodes was investigated. The SEM and XRD tests show that PbO2-ZrO2 nanocomposite electrodes possess finer grain size than PbO2 electrodes. The service life of PbO2-ZrO2 nanocomposite electrodes reaches 298 h which is 4 times longer than that of PbO2 electrodes. The electrochemical measurements show that PbO2-ZrO2 nanocomposite electrodes possess higher oxygen evolution overpotential and larger active surface area than PbO2 electrodes. The electrocatalytic property of PbO2-ZrO2 nanocomposite electrodes was also examined for the electrochemical oxidation of rhodamine B (RhB) and good fitting was found using the relation for the pseudo-first order reaction. The bulk electrolysis shows that the PbO2-ZrO2 nanocomposite electrodes exhibit the higher RhB and COD removal efficiency than PbO2 electrodes.

In this work, PbO2 electrodes were prepared by pulse electrodeposition in the lead nitrate plating bath. Effects of duty cycle on the morphology and phase structure were investigated by scanning electronic microscopy (SEM) and X-ray diffraction (XRD), respectively. The SEM and XRD results show that the decrease of duty cycles decreases the grain size of PbO2 electrodes. The steady-state polarization curves and accelerated life tests demonstrate that the oxygen evolution overpotential and service life of PbO2 electrodes increase with the decrease of duty cycle, the PbO2 electrodes prepared at 20 % duty cycle possess highest oxygen evolution overpotential and service life, and the service life of PbO2 electrodes prepared at 20 % duty cycle reaches 71 h which is almost two times longer than that of the PbO2 electrodes prepared by direct electrodeposition. The bulk electrolysis shows that the methyl orange (MO) degradation on the PbO2 electrodes prepared by pulse electrodeposition is the pseudo-first-order reaction and the chemical oxygen demand and MO removal on PbO2 electrodes increase with the decrease of duty cycle, which can be attributed to the higher oxygen evolution overpotentials and electrochemical active surface area of PbO2 electrodes.

Ni-W/ZrO2 nanocomposite coatings were prepared by electrodeposition in Ni-W plating bath containing ZrO2 nanoparticles. The influences of preparation parameter, such as ZrO2 nanoparticles concentration, current density and stirring rate, on weight percentage of codeposited ZrO2 nanoparticles in the nanocomposite coatings were investigated. The surface morphology of Ni-W/ZrO2 nanocomposite coating was characterized by scanning electron microscopy (SEM). The microhardness, wear resistance and corrosion resistance properties of Ni-W/ZrO2 nanocomposite coatings were studied. The results indicated that the addition of ZrO2 nanoparticles leads to an increase in microhardness and wear resistance of the nanocomposite coatings and a reduction in the wear weight loss. The corrosion behaviour of Ni-W/ZrO2 nanocomposite coatings was evaluated by the anodic polarization curves and weight loss measurements. The results revealed that Ni-W/ZrO2 nanocomposite coating has better corrosion resistance than the Ni-W alloy coating.

The influence of ZrO2 particles on fluorine-doped lead dioxide electrodeposition process on the glass carbon electrode (GCE) from lead nitrate electrolytes was studied by cyclic voltammetry (CV) and chronoamperometry (CA), coupled with the scanning electron microscope (SEM). Instantaneous nucleation mechanism is found for fluorine-doped lead dioxide electrodeposition in the presence of ZrO2 particles according to Scharifker–Hills’ model with three-dimensional growth. The results show that the addition of ZrO2 particles decrease the active surface area of the GCE, and the growth of the lead dioxide crystallites was obstructed.

PbO2–ZrO2 nanocomposite electrodes were prepared by the anodic codeposition in the lead nitrate plating bath containing ZrO2 nanoparticles. The influences of the ZrO2 nanoparticles concentration, current density, temperature and stirring rate of the plating bath on the composition of the nanocomposite electrodes were investigated. The surface morphology and the structure of the nanocomposite electrodes were characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD), respectively. The experimental results show that the addition of ZrO2 nanoparticles in the electrodeposition process of lead dioxide significantly increases the lifetime of nanocomposite electrodes. The PbO2–ZrO2 nanocomposite electrodes have a service life of 141 h which is almost four times longer than that of the pure PbO2 electrodes. The morphology of PbO2–ZrO2 nanocomposite electrodes is more compact and finer than that of PbO2 electrodes. The relative surface area of the composite electrodes is approximately 2 times that of the pure PbO2 electrodes. The structure test shows that the addition of ZrO2 nanoparticles into the plating bath decreases the grain size of the PbO2–ZrO2 nanocomposite electrodes. The anodic polarization curves show that the oxygen evolution overpotential of PbO2–ZrO2 nanocomposite electrodes is higher than PbO2 electrodes. The pollutant anodic oxidation experiment show that the PbO2–ZrO2 nanocomposite electrode exhibited the better performance for the degradation of 4-chlorophenol than PbO2 electrode, the removal ratio of COD reached 96.2%.