Facile microwave-assisted synthesis and controllable architecture of three-dimensional nickel titanate

Abstract

A rapid, facile, one-pot microwave-assisted polyol synthesis of novel hierarchical nickel titanate (NTN) is first reported in the present study. This method successfully fabricated rhombohedral NiTiO₃ in the shape of a cylindrical storage tank with two elliptical end caps that were constructed from ellipsoid-like nanoparticles. By contrast, irregular NTN aggregates composed of loose granular particles were formed through solvothermal treatment. Varying the dielectric of the solvent with water, n-butanol, acrylic acid, N,N-dimethylformamide, and an ethylene glycol : butanol mixture significantly affected the crystallographic structure and morphology of the final products due to differences in the loss tangent of each medium under microwave irradiation. Using a nickel source with acetate and halide counterions, which are more readily substituted and have better coordination ability with metal cations than nitrate, resulted in the formation of 3D hexagonal prismatic NiTiO₃ and undesirable 1D rod-like TiO₂ aggregates, respectively. Notably, this study provides a valuable means of developing a rapid, effective method to synthesize NiTiO₃ with uniform morphology, high purity and potential photocatalysis application.