Preparation of nano-Cu2O/TiO2 photocatalyst from waste printed circuit boards by electrokinetic process

It is difficult for separation and reutilization of Cu in waste printed circuit boards (PCBs) due to the heterogeneous mix of polymer materials, multiple kinds of metals and glass fiber. In this study, waste PCBs were pretreated by supercritical water oxidation (SCWO), then introduced into an electrokinetic (EK) system with nano-TiO(2) suspension as catholyte. In the EK process, Cu could be leached and reduced separately from the complicated multi-metal system in cathode compartment, and Cu(2)O could be formed in nano-size on TiO(2) surface. The properties of the composite catalysts Cu(2)O/TiO(2) were examined and their photocatalytic efficiencies were determined for methylene blue (MB) degradation. The results indicated that the catalytic effect increased with increasing EK preparation time but decreased afterwards. The most effective catalyst (4.53 wt.% Cu(2)O/TiO(2)), whose degradation ability was found to be much higher in comparison with commercial P25, was prepared by 6h EK treatment. It was found that the loading of Cu(2)O on TiO(2) surface could greatly enhance the photocatalytic effect of the catalyst. It is believed that the EK technology is effective and green for direct preparation of high value-added Cu nanocomposite materials from waste PCBs or other Cu-rich wastes.