Non-fluorinated synthesis of anatase TiO2 with dominant {001} facets: influence of faceted structures on formaldehyde sensitivity†
Abstract
Titanium dioxide (TiO2), the most widely investigated metal oxide due to its extraordinary surface, electronic and catalytic properties, is better manifested with exposed {001} facets. This article delineates the room temperature synthesis of TiO2 with 90% exposed {001} facets without using any fluorine containing precursor or hazardous material. Cetyltrimethylammonium bromide (CTAB) is explored as a capping agent to suppress the growth of the thermodynamically stable (101) plane. The {001} faceted nanosheets are decorated with gold nanoparticles of mean diameter 10 nm. The materials are characterized using XRD, TEM, XPS, as well as UV-vis, Raman and photoluminescence spectroscopy. The surface reactivities of different facets of TiO2 are substantiated in the light of formaldehyde (HCHO) oxidation. The synergistic effect between the reactive {001} facet of TiO2 and gold nanoparticles towards the photocatalysis of HCHO is also investigated and corroborated using mass spectroscopy.