Environmental pollution has become the main concern to humans [1,2]. In the point of view of numerous and permanent solar energy, photocatalysis has attracted much attention worldwide in environmental improvement and energy generation in the last years [3-5]. Herein, the synthesis of cobalt(II,III) oxide QDs-Ag2MoO4 heterojunction was reported by hydrothermal method and identified by different techniqs such as FT-IR, XRD, FE-SEM, EDS, TEM, DRS, PL, and UV–Vis spectroscopy. The SEM images illustrate that silver molybdate particles and cobalt(II,III) oxide QDs-AMO have a morphology of 3D-hexagons and nanosheets collected on the surface of 3D-hexagons with an average size of 36 and 28 nm, respectively. The cobalt(II,III) oxide QDs- silver molybdate photocatalyst was used toward the decolorization of MB with a conversion rate of 91%, which is 15 times faster than pure AMO. The higher photocatalyst activity of cobalt(II,III) oxide QDs-AMO should be attributed to its lower charge recombination rate in compared with pure silver molybdate . The stability of this photocatalyst was determind by reusing of it for five times without a remarkable decline in its activity. In addition, a postulated mechanism by the hydroxyl radical way was suggested.
