Facile synthesis of hierarchical CuS microspheres with high visible-light-driven photocatalytic activity

Abstract To date, a large volume of research has focused on the synthesis of microsphere photocatalysts with a hierarchical structure due to their high recovery efficiency and large specific surface area resulting in high photocatalytic activity. Nonetheless, the development of a facile approach to designing and controlling the morphology of microspheres has remained a challenge. In this study, well-controlled hierarchical CuS microspheres were synthesized via the simple chemical transformation of CuO templates prepared by an ultrasonic spray pyrolysis process which is an efficient form of solution aerosol thermolysis. The transformation rate was controlled by the ratio of CuO template and sulfur precursor, which enabled the implementation of a clear hierarchical structure. Time-series sulfurization experiments indicate that how the hierarchical shape evolved. The hierarchical CuS microsphere synthesized under optimal synthetic conditions shows excellent photocatalytic activity, Rhodamine B, methylene blue and methyl orange dye molecules were readily decomposed by the CuS microsphere, each having photocatalytic performance of 11.1, 8.3 and 32.0 times greater than commercial TiO2 nanoparticles. Furthermore, the degradation rate after fiver cycles is still above 95 %, indicating that the CuS microsphere was not deactivated and that stability and reusability were excellent.