Laser pyrolysis synthesis of zinc-containing nanomaterials using low-cost ultrasonic spray delivery of precursors

Laser pyrolysis employs a laser to selectively heat and decompose nanoparticle precursors, inducing particle formation. While gaseous precursors are most common, liquid precursors would reduce cost and safety issues. Sufficiently volatile liquids can be delivered from a bubbler, but such precursors are unavailable for many metals. Spray-based delivery can accommodate both pure liquids and solutions of solid precursors. Here, we demonstrate low-cost ultrasonic spray delivery of precursor solutions for laser pyrolysis synthesis of zinc-containing nanomaterials. Using zinc acetate and thiourea produced nitrogen-doped ZnS nanoparticles in both wurtzite- and sphalerite-rich phases, while sub-10 nm zinc sulfide and zinc oxide nanoparticles were produced from zinc acetate and thioacetamide, or zinc acetate alone, respectively. Finally, we produced spherical and rod-like zinc fluoride nanoparticles under conditions where the photosensitizer, SF₆, decomposes. These results demonstrate the potential of ultrasonic spray laser pyrolysis to produce materials of varied composition, crystal structure, and morphology.