Recent advances and remaining barriers to the development of electrospun nanofiber and nanofiber composites for point-of-use and point-of-entry water treatment systems.

In this review, we focus on electrospun nanofibers as a promising material alternative for the niche application of decentralized, point-of-use (POU) and point-of-entry (POE) water treatment systems. We focus our review on prior work with various formulations of electrospun materials, including nanofibers of carbon, pure metal oxides, functionalized polymers, and polymer-metal oxide composites, that exhibit analogous performance to media (e.g.

Synthesis and optimization of Fe₂O₃ nanofibers for chromate adsorption from contaminated water sources.

In this work, α-Fe2O3 nanofibers were synthesized via electrospinning and characterized to observe optimal morphological and dimensional properties towards chromate removal. The Fe2O3 nanofiber samples were tested in aqueous solutions containing chromate (CrO4(2-)) to analyze their adsorption capabilities and compare them with commercially-available Fe2O3 nanoparticles. Synthesized Fe2O3 nanofibers were observed with a variety of different average diameters, ranging from 23 to 63 nm, while having a constant average grain size at 34 nm, point zero charge at pH 7.

Synthesis and optimization of Ag-TiO2 composite nanofibers for photocatalytic treatment of impaired water sources.

In this work, Ag-TiO2 composite nanofibers were fabricated by electrospinning, where the composition and crystallinity were tuned by controlling the precursor composition and annealing conditions. Characterization revealed that bulk-embedded Ag nanoparticles inhibited anatase-to-rutile phase transformation and a decrease in band gap from 3.2 down to 2.

Hydroxyl radical formation during ozonation of multiwalled carbon nanotubes: performance optimization and demonstration of a reactive CNT filter.

We explored factors influencing hydroxyl radical (•OH) formation during ozonation of multiwalled carbon nanotubes (MWCNTs) and assessed this system's viability as a next-generation advanced oxidation process (AOP). Using standard reactivity metrics for ozone-based AOPs (RCT values), MWCNTs promoted •OH formation during ozonation to levels exceeding ozone (both alone and with activated carbon) and equivalent to ozone with hydrogen peroxide. MWCNTs oxidized with nitric acid exhibited vastly greater rates of ozone consumption and •OH formation relative to as-received MWCNTs.

Tailored synthesis of photoactive TiO ₂ nanofibers and Au/TiO ₂ nanofiber composites: structure and reactivity optimization for water treatment applications.

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.