Civil Engineering ETDs

Publication Date

Summer 6-28-2023

Abstract

This is partial fulfillment of a dissertation defense on electrochemical detection of Arsenic (As) in water using gold (Au) nanofilms as sensing electrodes. The maximum contaminant level of Arsenic in drinking water is set at 10 g L-1 by the WHO and USEPA. Electrochemical detection by linear stripping voltammetry has comparable detection limits to more expensive laboratory-based methods but with added benefits of being portable and manufacturable. The work has developed sputtered and crystallographically oriented nanofilms for detection of trace As (III). Ultraflat Au(111) oriented thin films, Au(UTF), were compared to single crystal model electrodes to identify the impacts of controlled surface atom geometry during fundamental electrochemistry studies. We found that the Au(111) surface structure had the highest sensitivity and selectivity for As (III) detection and the Au(UTF) performed very similar to the Au(111) single crystal model electrode for detection of As (III). The Au(UTF)s were then tested to determine the ability to detect trace As when its primary competing contaminant, Cu (II), was also present. Experiments with As & Cu mixtures provided evidence of an intermetallic alloy which had a large impact on the ability to detect trace As at the Au(UTF) surface. This study has implications for manufacturable and low Au loading sensing electrodes. The work is intended to increase availability of high sensitivity detection of As in drinking water for rural areas where mining legacies and groundwater usage have resulted in increased exposure to As (III).

Keywords

Arsenic, Electrochemical Detection, Water Sensors, Well Oriented Au(111) Surfaces, Nanofilms

Sponsors

Jose M. Cerrato & Fernando H. Garzon

Document Type

Dissertation

Language

English

Degree Name

Civil Engineering

Level of Degree

Doctoral

Department Name

Civil Engineering

First Committee Member (Chair)

Jose Manuel Cerrato Corrales

Second Committee Member

Fernando Garzon

Third Committee Member

Abdulmehdi Ali

Fourth Committee Member

Kerry Howe

Fifth Committee Member

Juan M. Feliu

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