Room-temperature synthesis of high-density CuS nanowire arrays by a simple paired cell

High-density CuS nanoparticle nanowire (NPNW) arrays were successfully synthesized at room temperature by a simple paired cell method. The as-prepared nanowire arrays were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The results indicate that the nanowire diameter is dependent on the pore size of the used ordered porous anodic alumina (OPAA) template and larger than the corresponding pore diameter of the template due to the corrosion effect of Na2S solution on the template. The nanowire is composed of CuS nanoparticles with hexagonal structure. When the reaction time is long enough, the nanowire is solid and composed of nearly spherical CuS nanoparticles. When the reaction time is short, only middle part of the nanowire is solid and composed of nearly spherical CuS nanoparticles, however, the tops are hollow and mainly composed of flake-like nanoparticles. The formation mechanism of CuS nanoparticle nanowires was proposed to be a heterogeneous nucleation, coalescence, aggregation and filling process.