A facile synthesis of spherical Cu-Ag architectures and their excellent catalytic performance

Nitroaromatic compounds are common toxic matters discharged as wastewater in varied industries. Reducing them into corresponding aromatic amines can not only decrease their contamination but also obtain value-added products, in which the preparation of catalysts with superior properties is the key. Herein, the spherical Cu-Ag architectures (ATs) are constructed via a two-step wet chemical method. First, the Cu microspheres are fabricated with the assistance of polyvinylpyrrolidone (PVP) in the mixed solution of ethylene glycol (EG) and water. Then, using them as templates, the spherical Cu-Ag ATs can be grown and constructed. The as-obtained Cu-Ag ATs have the spherical outlines assembled by many nanoparticles. The sliced Cu-Ag ATs show hollow structures and many nanothorns grow from the center to the around, combining the roughly spherical shell to build up the Cu-Ag ATs. In the reduction reaction of p-nitrophenol and p-nitroaniline, the spherical Cu-Ag ATs all exhibit excellent catalytic activities. Within 85 s and 80 s, the p-nitrophenol and p-nitroaniline can be converted completely. The prepared Cu-Ag ATs are expected to have potentials in other fields, such as electronics, sensors and so on.

The hierarchical Cu-Ag architectures are constructed successfully through a two-step wet chemical method, in which the rough Cu microspheres are first fabricated in aqueous EG solution, and are used as templates to direct the growth of Cu-Ag architectures. In both reduction of p-nitrophenol and p-nitroaniline, the Cu-Ag architectures exhibit high catalytic activities.