Item Details

title

Next Generation Sustainable Drinking Water Treatment via Functional Nanomaterials

author

Aragon, Alexander Gennadivich

abstract

Water is a critical resource for sustaining life on Earth, and many individuals throughout the world have very limited access to clean water. With the ever-growing global population and need to have clean water, the scientific community has been seeking ways to either treat and reuse wastewater, or find new water sources, etc., as many of the planet’s natural water is inaccessible in glaciers, and groundwater wells. Thus, the need for sustainable, cost-effective, and high efficiency methods for cleaning drinking water sources is necessary. Nanomaterials have been shown to be very useful agents for treating water to drinking water quality standards whether through the direct oxidation of organic contaminants, serving as adsorbents for toxic metals, or as antibacterial agents. Metal oxide and metal halide perovskite nanoparticles have been utilized for a variety of commercially relevant applications such as solar cells, light emitting diodes, computer chips, and batteries due to their extraordinary optoelectronic properties. Despite the potential for wide application in water treatment, there are a few concerns for these materials: stability, optimizing light absorption, and environmental toxicity.In the world of water treatment, all inorganic lead halide perovskite NCs have attracted attention as photocatalysts for the degradation of organic pollutants. Their strong visible light absorption, and high charge-carrier efficiency allows for high efficiency oxidation of pollutants. However, their long-term toxicity concerns and weak stability in polar solvents hold back the potential for their extended use in water treatment. Therefore, building stable and lead-free perovskites that are strong agents for the treatment of water is a major focus of this dissertation along with developing amended metal oxide photocatalysts for the treatment of drinking water through alternative synthetic methods. In this dissertation, lead-free bismuth-based alternative halide perovskites were employed as a model in search of new nanomaterials for water treatment. It was found that the use of Bi-based perovskite alternatives is a strong candidate for the degradation of organic pollutants given the inherit greater stability than CsPbBr3 NCs and higher efficiency than P25 TiO2, a commercially available photocatalyst. The antibacterial properties of Bi-based double perovskite NCs were also investigated as a model drinking water treatment method. As synthesized Cs2AgBiBr6 and Cs2NaBiBr6 NCs were shown to have strong antibacterial efficiency given the observed high log E. coli inactivation, with increased activity for the Ag analog likely due to the presence of Ag, which has a long history of being used in medicine. Another overarching theme of this work was to develop alternative water treatment methods based on photocatalysis. Metal oxide semiconductors, such as ZnO and TiO2 have typically been used as antibacterial agents and as photocatalysts and thus present a strong platform for the development of water treatment technologies. Though surface area and reusability remain a large concern for the commercialization of these technologies, and a solution to this is presented through the utilization of atomic layer deposition (ALD) for the deposition of metal oxide photocatalysts on meltblown nonwoven fabrics.

subject

Atomic Layer Deposition

Lead-Free Perovskites

Metal Oxides

Nanomaterials

Photocatalysis

Water Treatment

contributor

Young, Kyana RL (advisor)

Straker, Leslie (committee member)

Donati, George L (committee member)

Jones, Amanda C (committee member)

King, Bruce S (committee member)

Lachgar, Abdessadek (committee member)

date

2023-07-25T17:48:38Z (accessioned)

2023-12-06T09:30:05Z (available)

2023 (issued)

degree

Chemistry (discipline)

embargo

2023-12-06 (terms)

identifier

http://hdl.handle.net/10339/102251 (uri)

language

en (iso)

publisher

Wake Forest University

type

Dissertation