Preparation and enhanced photocatalytic activity of Pd–CuO/palygorskite nanocomposites

Silicate nanofibers (palygorskite, Pal) coated with CuO nanoparticles were prepared via a precipitation method using copper oxalate as a precursor and subsequently modified with PVP–Pd solution. Characterization by X-ray diffraction and transmission electron microscope demonstrated that the surfaces of the Pal fibers with 20–30 nm in diameter and 400–500 nm in length were uniformly decorated with CuO nanoparticles of 16 nm in average size. The CuO/Pal and Pd–CuO/Pal nanocomposites exhibited higher photocatalytic activities than the pure CuO for the photodegradation of methyl orange under UV-light. The enhanced photocatalytic activity of CuO/Pal and Pd–CuO/Pal composites may be ascribed to the surface adsorption and efficient electron–hole separation at the coupled interface. The combination of nanoparticles and nano-scale fibers can lead to a remarkable improvement in photocatalytic activity; this concept can be expected to find interesting applications in the environmental field.