Effects of Ag nanoparticles on the visible-light-driven photocatalytic properties of Cu2O nanocubes

Highlights: • Ag nanoparticles grow on surfaces of single-crystalline Cu₂O nanocubes. • Ag nanoparticles greatly enhance photocatalytic activity of Cu₂O nanocubes. • There is an optimum content of Ag for Cu₂O to achieve the best performance. • A photocatalytic model of the Ag–Cu₂O based on band structure is proposed. -- Abstract: Cu₂O nanocubes decorated with Ag nanoparticles were synthesized based on a one-step wet chemistry approach. The content of Ag nanoparticles was adjustable by tuning the AgNO₃ concentration. The photocatalytic performances of the Ag/Cu₂O nanocubes were systematically evaluated, and the influences of the Ag nanoparticles were analyzed. The introduction of Ag nanoparticles reduced the band gap, increased the photocurrent and most importantly enhanced the photocatalytic activity towards organic pollution degradations under visible light illumination. There is an optimum content of Ag nanoparticles for the Ag/Cu₂O nanocubes to achieve the best performances. A model based on the band structure theory is proposed to explain the excellent performance of the Ag/Cu₂O nanocubes.