Template-free one-step fabrication of porous CuInS2 hollow microspheres

Hollow CuInS2 microspheres have been successfully prepared via a simple solution-based route without employing templates and surfactants. Transmission electron microscope (TEM) images clearly show the hollow nature of the as-obtained products. Field emission scanning electron microscopy (FESEM) images reveal that the shells of as-prepared CuInS2 microspheres were constructed by nanoparticles or nanoflakes. The specific surface area and pore-size distribution of the obtained product as determined by gas-sorption measurements show that the CuInS2 hollow microspheres exhibit high Brunauer–Emmett–Teller (BET) surface area and porosity properties. TEM observations of intermediate products at different reaction stages indicate that these hollow CuInS2 microspheres are formed mainly via Ostwald ripening.