Macroporous TiO2 and Graphite-like Carbon Hybrid Hierarchical Interfaces for Improved Photocatalytic Activity Derived from Particle-Stabilized Emulsions

Abstract

Hierarchical macroporous TiO2/graphite-like carbon hybrid photocatalyts were successfully prepared by a facile method employing a particle-stabilized high internal phase emulsion (Pickering emulsion) as the template and sucrose as the carbon source. The results of this study showed that mesopores, with diameters ranging from 10 to 50 nm, were homogeneously distributed on the cell-window structured macropore walls that were armored by nano-sized TiO2 particles. Moreover, a microporous graphitic layer of thickness ∼2 nm surrounded the surface of the TiO2 particles. This type of hierarchical macro-meso-microporous structure with high-efficiency diffusion and mass transfer properties, along with the porous graphitic layers with a high BET surface area, resulted in a hybrid catalyst possessing high adsorption rate and capacity. In addition, the carbon layers suppressed the transition temperature of titania (anatase to rutile) by more than 200 °C. The green method presented here can potentially be employed for the preparation of cost-effective environmental materials toward the degradation of dyes and other pollutants.