Versatility of One-pot, Single-step Synthetic Approach for Spherical Porous (Metal) Oxide Nanoparticles Using Supercritical Alcohols

摘要

We developed a rapid, one-pot, single-step synthetic method for preparing spherical porous (metal) oxides, titanium dioxide, silica, zirconium dioxide, cerium dioxide, and zinc oxide with large surface areas in a supercritical alcohol containing formic acid or phthalic acid as organic additive in a very short reaction time (10 min). A new type of hollow TiO_2 nanoparticle was obtained by slowly heating the reaction mixtures. The shell thickness of hollow TiO_2 nanoparticles was controlled by adjusting the heating rate. The method proved highly versatile for synthesizing solid and hollow spherical meso/microporous nanoparticles. The spherical mesoporous TiO_2 nanoparticles photocatalytically degraded methylene blue in water under UV irradiation, and successfully transported DNA under biolistic bombardment.