Enhanced photocatalytic degradation of methylene blue in aqueous solution by Cu/ZnO photocatalyst

In order to improve the photocatalytic activity of ZnO nanorod, the Cu/ZnO nanorod was modified by copper sulfate (CuSO4) and ZnO nanorod. Transmission electron microscope (TEM) was carried out to characterize the composites with different Cu contents, indicating that the modification does not alter the length and diameter of ZnO nanorod. The photocatalytic degradation of methylene blue (MB) was chosen as a model reaction to evaluate the photocatalytic activities of ZnO and Cu/ZnO nanorod. Cu/ZnO shows significantly higher photocatalytic activity (k(app) = 0.0402 min(-1)) than ZnO nanorod (k(app) = 0.0172 min(-1)) under sunlight irradiation. The degradation of MB accords with pseudo-first order kinetics, and the appear rate constants k(app) of 7% Cu/ZnO nanorod was about 2.3 times higher than ZnO nanorod. The optimum synergetic effect was found at a weight ratio of 7.0 wt % (Cu/ZnO), and the optimum synergetic factor was 2.34.