Synthesis of three-dimensional agaric-like biomorphic TiO2 by a facile method with Coscinodiscus sp. frustule

Abstract

The paper aims to expand the application of natural marine algae. Marine diatoms, which have intricate frustule structures, can serve as bio-template for preparing three-dimensional materials. A simple and effective approach to synthesize the corrugated agaric-like biomorphic TiO2 templated with frustule of Coscinodiscus sp. is reported. In the sol-gel preparation process, the titania-coating on the frustule is prepared through the deposition and condensation with the aid of acetylacetone (acac) as a controlling agent to make the precursor Ti(BuO)4 hydrolyze slowly. The as-prepared titania-coated frustule and biomorphic TiO2 is characterized by scanning electron microscopy (SEM) attached with energy dispersive X-ray spectrometer (EMAX) and X-ray diffraction (XRD). The microstructure of the corresponding titania nanoparticles appears to be sphere with the diameters distributed around 10–20 nm. The templating process is repeated for three cycles. Subsequently, the three-dimensional freestanding corrugated agaric-like biomorphic TiO2 structure is obtained by a selective removal in the NaOH solution. As far as we known, the 3D freestanding corrugated agaric-like biomorphic TiO2 with greatly increased surface area is obtained for the first time.