Enhanced degradation effect of nano-PAA-CuCl2 with controllable 3D structure as heterogeneous Fenton-like catalyst over a wide pH range

Dye wastewater treatment has been a hot spot of scientific research and technological development. One kind of porous CuCl2 film with controllable three-dimensional structure was synthesized on the top surface of nanoporous anodic alumina (nano-PAA) by self-assembled method. The nano-PAA-CuCl2 film and H2O2 form a heterogeneous Fenton-like catalytic system, and the catalysts were characterized by EDS, XPS and FE-SEM. Then, the main parameters affecting the degradation of Rhodamine B (RhB) were investigated in detail. Under the optimum experimental conditions, i.e., initial pH 3.3, initial H2O2 concentration 14 mmol/L, nano-PAA-CuCl2 generated with 8 x 10(-4) mol/L CuCl2 solution, RhB was completely degraded four times. Even the degradation rates were still as high as 97.1% and 94.8% when the nano-PAA-CuCl2 catalyst was reused for the fifth and sixth times, respectively. In addition to enhancing the catalytic activity, the pH of the treated solution had a wide range value, i.e., 2-8, with an optimal value of 5.8. At last in the paper, a degradation mechanism of heterogeneous Fenton-like catalytic degradation of RhB by nano-PAA-CuCl2/H2O2 system is proposed, the reaction kinetics accorded with the pseudo-first-order equation. All the results indicate that the nano-PAA-CuCl2 has practical prospects for H2O2-driven Fenton-like treatment of organic dye wastewater, with the advantages of green and cost-effective, stability and reusability.