Mechanochemical Synthesis of TiO2 Nanoparticles and Their Self-organization at Interfaces to Produce Emulsion-Templated Photocatalytic Porous Polymers

Abstract

Mechanochemical synthesis methods are solid-state processes that constitute an alternative to those based on the use of liquid solvents. Mechanochemical methods have potential for industrial use as they are simple, scalable and environmental friendly. The solid-state reactions in mechanochemical synthesis can be used to obtain nanoparticles with small size and well-controlled crystallinity, at very low cost. Herein, we report on the mechanochemical synthesis of TiO2 photocatalytic nanoparticles, with controlled particle size and crystalline structure. Moreover, we also show that the bandgap of these TiO2 nanoparticles can be modified by carbon doping, so that they can display photocatalytic activity under visible light. The photocatalytic performance of various TiO2 nanoparticles has been evaluated by measuring the degradation of dyes. Moreover, upon convenient surface hydrophobization, the TiO2 nanoparticles can adsorb on liquid/liquid interfaces and become good stabilizers for highly concentrated emulsions. Such particle-stabilized emulsions were used as templates for the preparation of macroporous photocatalytic materials with a polymer matrix (photocatalytic polyHIPE).