Cu2O/MoS2 composites: a novel photocatalyst for photocatalytic degradation of organic dyes under visible light

The novel nanocomposite Cu2O/MoS2-12 was synthesized by a simple two-step method. Cu2O nanospheres grow on the surface of MoS2 nanoflowers and have high photocatalytic activity. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) X-ray photoelectron spectroscopy (XPS), ultraviolet-visible light (UV-vis) photoluminescence (PL) spectroscopy, UV-vis diffuse reflection (UV-DRS), and electrochemical impedance (EIS) were used to study the structure and properties of the samples. The photocatalytic properties of the materials were evaluated by degrading methyl orange (MO) under visible light. The results show that CM-12 can completely degrade MO in 30 min, and the pseudo-first-order kinetic constant of degradation is 8.76 times that of pure Cu2O, which can be attributed to the composite material that can greatly reduce the recombination rate of photogenerated electrons and holes, and it has good stability. After repeated use for 5 times, the degradation rate can still reach 40%. Through experiments and theoretical results, a possible photocatalytic mechanism is proposed. To the best of our knowledge, this work was the first example of combining MoS2 with Cu2O and applying it to photocatalytic degradation of organic pollutants. It was beneficial for developing new photocatalysts and improving the catalytic performance of conventional photocatalysts.