Surfactant assisted sonochemical synthesis of hollow structured zinc phosphate nanoparticles and their application as nanocarrier

• Novel hollow zinc phosphate nanospheres were fabricated without template.
• The formation mechanism for the hollow nanospheres was studied.
• Synthesized hollow nanospheres thermally stable and having large surface area.
• The hollow nanospheres exhibited excellent loading capacity for imidazole.

This work reports, the facile surfactant assisted sonochemical route for the synthesis of hollow zinc phosphate nanoparticles. The prepared material was analyzed by Fourier transform infrared, X-ray diffraction, Brunauer–Emmett–Teller nitrogen adsorption/desorption isotherms, field emission scanning electron microscopy, transmission electron microscopy and thermo gravimetric analysis confirm the successive formation of well-organized hollow spherical structure of zinc phosphate. The diameter and the shell thickness of the hollow particles are typically in the range of 20–40 nm and 5–7 nm respectively. The specific surface area and the total pore volume of the synthesized hollow zinc phosphate nanoparticles were found to be 100.15 m2/g and 0.1384 cm3/g respectively. A possible growth mechanism for the formation of hollow zinc phosphate nanospherical structures has been proposed, which is considered to be a sonochemically induced a surfactant vesicle-template formation. The prepared hollow zinc phosphate nanoparticles exhibits a sustained release behavior about 76.5 wt.% and 5.7 wt.% of the total loaded imidazole into the solution after 50 h at pH 6 and 10 respectively. The imidazole loaded hollow zinc phosphate nanoparticles can be potentially applied as a corrosion inhibitor in paint formulation.