Journal article
Tailored Synthesis of Photoactive TiO2 Nanofibers and Au/TiO2 Nanofiber Composites: Structure and Reactivity Optimization for Water Treatment Applications
Environmental science & technology, Vol.49(3), pp.1654-1663
02/03/2015
DOI: 10.1021/es502963t
Abstract
Titanium dioxide (TiO2) nanofibers with tailored structure and composition were synthesized by electrospinning to optimize photocatalytic treatment efficiency. Nanofibers of controlled diameter (30–210 nm), crystal structure (anatase, rutile, mixed phases), and grain size (20–50 nm) were developed along with composite nanofibers with either surface-deposited or bulk-integrated Au nanoparticle cocatalysts. Their reactivity was then examined in batch suspensions toward model (phenol) and emerging (pharmaceuticals, personal care products) pollutants across various water qualities. Optimized TiO2 nanofibers meet or exceed the performance of traditional nanoparticulate photocatalysts (e.g., Aeroxide P25) with the greatest reactivity enhancements arising from (i) decreasing diameter (i.e., increasing surface area), (ii) mixed phase composition [74/26 (±0.5) % anatase/rutile], and (iii) small amounts (1.5 wt %) of surface-deposited, more so than bulk-integrated, Au nanoparticles. Surface Au deposition consistently enhanced photoactivity by 5- to 10-fold across our micropollutant suite independent of their solution concentration, behavior that we attribute to higher photocatalytic efficiency from improved charge separation. However, the practical value of Au/TiO2 nanofibers was limited by their greater degree of inhibition by solution-phase radical scavengers and higher rate of reactivity loss from surface fouling in nonidealized matrixes (e.g., partially treated surface water). Ultimately, unmodified TiO2 nanofibers appear most promising for use as reactive filtration materials because their performance was less influenced by water quality, although future efforts must increase the strength of TiO2 nanofiber mats to realize such applications.
Details
- Title: Subtitle
- Tailored Synthesis of Photoactive TiO2 Nanofibers and Au/TiO2 Nanofiber Composites: Structure and Reactivity Optimization for Water Treatment Applications
- Creators
- Michael J Nalbandian - University of CaliforniaRiversideKatherine E Greenstein - University of IowaDanmeng Shuai - University of IowaMiluo Zhang - University of CaliforniaRiversideYong-Ho Choa - Hanyang UniversityGene F Parkin - University of IowaNosang V Myung - University of CaliforniaRiversideDavid M Cwiertny - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Environmental science & technology, Vol.49(3), pp.1654-1663
- Publisher
- American Chemical Society
- DOI
- 10.1021/es502963t
- ISSN
- 0013-936X
- eISSN
- 1520-5851
- Grant note
- DOI: 10.13039/100000139, name: U.S. Environmental Protection Agency, award: R835177
- Language
- English
- Date published
- 02/03/2015
- Academic Unit
- Civil and Environmental Engineering; Chemical and Biochemical Engineering; Center for Health Effects of Environmental Contamination; Public Policy Center (Archive)
- Record Identifier
- 9983992053202771
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