Microwave-assisted controllable synthesis of hierarchical CuS nanospheres displaying fast and efficient photocatalytic activities

Two types of hierarchical mesoporous CuS nanospheres, i.e., solid spheres (SSs) and hollow spheres (HSs), were controllably synthesized by a facile and green microwave-assisted wet chemical process, using copper acetate and thiourea aqueous solutions as precursors without a surfactant or template. The crystal structures, morphologies and photocatalytic properties of the products were characterized by various techniques. The results indicated that CuS SSs of 150 ± 50 nm in diameter are made of nanograins of about 10 nm in size, whereas CuS HSs of 400 ± 100 nm in outer-diameter are the assembly of ultrathin nanosheets in thickness of about 6 nm. The as-obtained both CuS architectures exhibit far superior dye degradation properties than commercial CuS powder for the decomposition of organic dyes including rhodamine B, methylene blue and malachite green with the help of hydrogen peroxide under visible light. Specially, using CuS HSs as catalyst, the decoloring rates of three organic dyes catalyst reach above 90% after just 1 min of irradiation and are approaching 100% after 20 min of irradiation, suggesting a fast and efficient photocatalytic activity and a promising application in industrial wastewater purification.