In situ loading of CuS nanoflowers on rutile TiO₂ surface and their improved photocatalytic performance

Graphical abstract: CuS nanoflowers, fabricated by an element-direct-reaction route using copper and sulfur powder, were loaded on rutile TiO₂ (CuS/TiO₂) at low temperature. In photocatalytic degradation of MB or 4-CP, it is found that the surface modification with CuS can enhance the photocatalytic efficiency of TiO₂. The promotion of photocatalytic performance is mainly ascribed to the enhanced charge separation originating from the well-matched heterostructure between CuS and rutile TiO₂. - Highlights: • CuS nanoflowers, fabricated by an element-direct-reaction route using copper and sulfur powder, were loaded on rutile TiO₂ at low temperature. • In the photo-degradation studies of MB and 4-CP, surface modification with CuS can enhance the photocatalytic efficiency of rutile TiO₂. • CuS/TiO₂ composite materials show the good repeatability of the photocatalytic activity. • This work provides a facile method to design and fabricate the effective composites photocatalyst. - Abstract: CuS nanoflowers, fabricated by an element-direct-reaction route using copper and sulfur powder, were loaded on rutile TiO₂ (CuS/TiO₂) at low temperature. CuS/TiO₂ composites were utilized as the photocatalysts for the degradation of Methylene Blue (MB) and 4-chlorophenol (4-CP). X-ray diffraction (XRD), UV Raman spectroscopy, transmission electron microscopy (TEM), XPS, and UV-visible diffuse reflectance spectra were used to characterize the crystalline phase, morphology, particle size, and the optical properties of CuS/TiO₂ samples. It is found that CuS/TiO₂ photocatalyst, which CuS are loaded on the surface of rutile TiO₂, exhibited enhanced photocatalytic degradation of MB (or 4-CP) than TiO₂ or CuS. This indicates that CuS can enhance effectively the photocatalytic activity of rutile TiO₂ by forming heterojunction between CuS and rutile TiO₂, which is confirmed by photoluminescence (PL) spectra and TEM. Moreover, CuS content has a significant influence on photocatalytic activity and 2 wt% CuS/TiO₂ showed the maximum photocatalytic activity for degradation of MB.