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

Size-controlled preparation of Cu2O nanoparticles from waste printed circuit boards by supercritical water combined with electrokinetic process

“…1. In EK system with an assisting agent HCl, copper oxide formed during SCW process could be leached, then the formed Cu 2+ migrated toward cathodic compartment under the electric field [16][17][18]. PVP introduced into the cathodic bath could coordinate with Cu 2+ to form multinuclear complexes on its chain, since each PVP monomer has a lactim group.…”

“…The SCW pretreatment was conducted in a 200-mL highpressure reactor made of 316 alloy, and hydrogen peroxide (H 2 O 2 , 30 wt%) was used as oxygen source [16][17][18]. H 2 O 2 is decomposed and the released oxygen can be dissolved in supercritical water (H 2 O 2 = H 2 O + 1/2O 2 ).…”

“…In our previous study [18], Cu 2 O/TiO 2 nanomaterials were prepared from waste PCBs by EK process. Cu in waste PCBs could be leached and reduced separately in cathode compartment of EK system, and Cu 2 O with average size around 50 nm could be formed on the surface of TiO 2 contained in catholyte.…”

Dye Waste Treatment

“…The study of the photocatalytic efficiencies of the composite catalyst nano-Cu 2 O/TiO 2 prepared using electrokinetic system (EK) on the degradation of Methylene Blue showed that the decomposition of the dye increased with increasing EK preparation time [19]. It was also found that the loading of Cu 2 O on the TiO 2 surface could greatly enhance the photocatalytic effect of the catalyst.…”

Recovery of metals from waste printed circuit boards by supercritical water pre-treatment combined with acid leaching process

“…At supercritical conditions (T > 374°C, P > 22.1 MPa), organic compounds and water form a single and homogeneous phase, which allows reaction to proceed rapidly by an elimination of the potential interface mass transport limitations (Modell, 1989;Shaw et al, 1991). At present, there are two main SCW processes used for the treatment of waste PCBs (Chien et al, 2000;Goto et al, 2003;Xiu and Zhang, 2009;Onwudili and Williams, 2009;Yin et al, 2011;Wang and Zhang, 2012). One is supercritical water oxidation (SCWO) process in the presence of oxygen, and the other is supercritical water depolymerization (SCWD) process under reducing atmosphere.…”