title: Porous TiO₂ materials through Pickering high-internal phase emulsion templating.
abstract: We report a facile method for preparing porous structured TiO2 materials by templating from Pickering high-internal phase emulsions (HIPEs). A Pickering HIPE with an internal phase of up to 80 vol %, stabilized by poly(N-isopropylacrylamide)-based microgels and TiO2 solid nanoparticles, was first formulated and employed as a template to prepare the porous TiO2 materials with an interconnected structure. The resultant materials were characterized by scanning electron microscopy, X-ray diffraction, and mercury intrusion. Our results showed that the parent emulsion droplets promoted the formation of macropores and interconnecting throats with sizes of ~50 and ~10 μm, respectively, while the interfacially adsorbed microgel stabilizers drove the formation of smaller pores (~100 nm) throughout the macroporous walls after drying and sintering. The interconnected structured network with the bimodal pores could be well preserved after calcinations at 800 °C. In addition, the photocatalytic activity of the fabricated TiO2 was evaluated by measuring the photodegradation of Rhodamine B in water. Our results revealed that the fabricated TiO2 materials are good photocatalysts, showing enhanced activity and stability in photodegrading organic molecules.
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong , Shatin N.T., Hong Kong.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Li
authors.forename: Guanqing
authors.initials: G
authors.lastname: Sun
authors.forename: Yecheng
authors.initials: Y
authors.lastname: Li
authors.forename: Jimmy C
authors.initials: JC
authors.lastname: Yu
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Ma
authors.forename: To
authors.initials: T
authors.lastname: Ngai
mesh_terms: D004655:Emulsions / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004655:Emulsions; C009495:titanium dioxide; D014025:Titanium