UV and Visible Light Induced Photocatalytic Degradation on p–n Cu 2 O/ZnO Nanowires Decorated with Au–Pd Alloy Nanoparticles

Abstract Chemical solutions are applied to synthesize Au–Pd alloy nanoparticles (NPs) and ZnO/Cu 2 O core–shell nanowires (NWs) on ITO/glass substrates by the photochemical, electrochemistry, and hydrothermal methods. The Cu 2 O cubic structures and ZnO hexagonal wurtzite structures are verified as being polycrystalline and single crystalline, respectively, by X‐ray diffraction and high‐resolution transmission electron microscopy (HR‐TEM). The p‐Cu 2 O/n‐ZnO NWs samples exhibit rectification properties that confirm the p–n heterojunction interface. The diameter range of the Au–Pd alloy NPs is around 2–15 nm and the Au/Pd ratio is 27:28, according to HR‐TEM and X‐ray photoelectron spectroscopy. The p‐Cu 2 O/n‐ZnO core–shell NWs feature higher UV photocatalytic degradation of methylene blue than do the ZnO NWs. Deposited Au, Pd, Au–Pd alloy NPs on the p‐Cu 2 O/n‐ZnO core–shell NWs improve the photocatalytic degradation efficiency under UV and blue light. The Au–Pd alloy NPs/p‐Cu 2 O/n‐ZnO core–shell NWs offer the best photocatalytic properties under UV‐ and blue‐light‐emitting diode (LED) illumination.