Fabrication and Degradation Properties of Nanoporous Copper with Tunable Pores by Dealloying Amorphous Ti-Cu Alloys with Minor Co Addition

3D bicontinuous nanoporous copper (NPC) with tunable structure was facilely synthesized by one-step chemical dealloying of Ti-Cu amorphous alloys with minor Co addition (0, 4 and 6 at.%). As-dealloyed NPC shows a sandwich-like hierarchical porous structure with micropore in the inner layer and mesopore in the outer layer. The pore size of NPC can be adjusted by the Co content and corrosion time. In addition, the minor Co element in the matrix alloy can promote the formation of more uniform pore and ligament of NPC, which was evaluated by the surface diffusivity of NPC. The formation mechanism of NPC was discussed using phase separation theory. The NPC/Cu₂O composite consists of a large number of 3D continuous ligaments and few tetrahedral Cu₂O particles grown on the NPC substrate. As catalysts, NPC/Cu₂O composite exhibits excellent degradation performance for methyl orange (MO) dye in the dark assisted by the ultrasonic irradiation due to hierarchical porous structure and the synergistic effect of Cu ligaments and Cu₂O particles. The relationship between the efficient MO degradation rate of NPC/Cu₂O catalysts and temperature has been discussed. Fenton-like reaction shows that NPC/Cu₂O catalysts supplemented with hydrogen peroxide (H₂O₂) can generate HO^· radicals, which resolve MO dye molecules into H₂O, CO₂ and inorganic species.