Sputtering control of Ag₂O decoration configurations on ZnO nanorods and their surface arrangement effects on photodegradation ability toward methyl orange

In this study, a combinational strategy for synthesizing ZnO nanorod arrays interlaced with Ag₂O particles was proposed. Hydrothermally derived ZnO nanorod templates were sputter coated with Ag₂O particles. The sputtered Ag₂O particles can be decorated on the surfaces of the ZnO nanorod arrays with a randomly dispersive or continuous coverage characteristic by controlling the sputtering duration. Structural analysis revealed the formation of satisfactory crystalline ZnO–Ag₂O composite nanorods through the hydrothermal and sputtering methods. The ZnO–Ag₂O composite nanorods exhibited a significantly enhanced photoactivity compared with that of pristine ZnO nanorods under light irradiation. Moreover, the Ag₂O content and the coverage feature of the ZnO–Ag₂O composite nanorods influence the photodegradation of methyl orange solution by the composite nanorods under light irradiation. The photodegradation efficiency of the ZnO nanorods was substantially enhanced when the Ag₂O particles were decorated on the surfaces in a dispersive manner. This can be attributed to the optimal content of Ag₂O particles and their randomly dispersive characteristic on the surface of the composite nanorods, which resulted in the efficient transfer of photocarriers and markedly suppressed the electron–hole recombination rate. (paper)