Photoelectrochemical synergetic degradation of Acid Orange II with TiO_2 modified β-PbO_2 electrode

Electrochemically assisted photocatalysis is an effective approach to improve photocatalytic efficiency. In this paper, modified β-PbO2 electrode was prepared by TiO2 co-deposition and characterized by SEM and XRD. Then 2.0 g TiO2 modified β-PbO2 electrode (2.0 g TiO2 involved in the 200 mL co-deposition solution) was used in electrochemically assisted photocatalytic degradation of Acid Orange II and the influence of initial pH values was investigated when the potential applied across the electrodes was 1.5 V. When the potential applied was 2.5 V, the difference of the degradation process and the final products were studied. The results indicated that 2.0 g TiO2 modified β-PbO2 electrode was different from the unmodified one in that the β-PbO2 crystals became finer and the electrode became more compact and more uniform. The synergetic effect in electrochemically assisted photocatalytic degradation of Acid Orange II was observed and degradation efficiency and TOC removal were the highest at initial solution pH 2.0. By UV-visible spectral analysis, it was proved that photoelectrochemical synergetic degradation of Acid Orange II went through the step of producing main product maleic acid for the solution at the initial pH 2.0 within 2 h, but the degradation was slow for the solution at the initial pH 12.0.

Electrochemically assisted photocatalysis is an effective approach to improvephotocatalytic efficiency. In this paper, modified beta-PbO_2 electrode was prepared by TiO_2co-deposition and characterized by SEM and XRD. Then 2.0 g TiO_2 modified beta-PbO_2 electrode (2.0g TiO_2 involved in the 200 mL co-deposition solution) was used in electrochemically assistedphotocatalytic degradation of Acid Orange II and the influence of initial pH values was investigatedwhen the potential applied across the electrodes was 1.5 V. When the potential applied was 2.5 V,the difference of the degradation process and the final products were studied. The results indicatedthat 2.0 g TiO_2 modified beta-PbO_2 electrode was different from the unmodified one in that thebeta-PbO_2 crystals became finer and the electrode became more compact and more uniform. Thesynergetic effect in electrochemically assisted photocatalytic degradation of Acid Orange II wasobserved and degradation efficiency and TOC removal were the highest at initial solution pH 2.0. ByUV-visible spectral analysis, it was proved that photoelectrochemical synergetic degradation of AcidOrange II went through the step of producing main product maleic acid for the solution at theinitial pH 2.0 within 2 h, but the degradation was slow for the solution at the initial pH 12.0.