My research is focused in three areas: 1) environmental interfaces, specifically atmospheric reactions that occur on mineral dust surfaces with trace pollutant gases, 2) using a combinatorial approach to identifying semiconducting materials that can efficiently split water into hydrogen and oxygen using sunlight or reduce carbon dioxide into a useable fuel sources, and 3) science education, specifically in developing learning progressions for students from 6th grade to introductory collegiate courses that is centered around quantitative reasoning in ecology for environmental literacy.
Interest I: Environmental Interfaces
Our interest in environmental chemistry occurs at both atmospheric interfaces (e.g. clay mineral reacted with methane, SO2, and CO2) as well as solid/solution interfaces that occur in the environment. A lack of understanding exists on the role these interfaces in the environment, especially under irradiation. A reaction chamber has been built to investigate the solid/gas and the solid/liquid/gas interfaces under irradiation.
Our laboratory uses a number of instruments such as Attenuated Total Reflectance (ATR)-Fourier transform infrared spectroscopy (FTIR) and Gas Chromatograph-Mass Spectrometry (GC/MS) as well as UV-VIS Spectroscopy, X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) to characterize natural and synthetic samples. By better understanding the properties and reactions that occur that these interfaces and the products that are produced, we can better inform atmospheric modelers to improved understanding of climate change.
Interest II: Combinatorial Chemistry with an Energy Emphasis
The Solar Hydrogen Activity research Kit (SHArK) Project provides a unique, hands-on approach to developing and characterizing new materials to solve these problems. We use the following systems to investigate new combinations of materials that could be potentially photoactive towards water splitting or reduction of CO2. These combinations are Copper/Zinc, Copper/Zinc/Iron, Manganese/Magnesium/Bismuth, Bismuth Vanadate/M (where M = Zn, Co, Mn, and Mg), and Magnesium/Iron/Copper.
A picture of the two scan stations used for determination of the photoactivity are shown in Figure 1.
Figure 1: The two scan stations used in the Solar Army. a) Shows the LEGO scan station (left) and b) shows the new light emitting diode (LED) system recently deployed (right).
Student collected data is shown in Figure 2 with the photoactivity being represented by the bar height. At UW-Oshkosh, samples are spray deposited on a heated custom built mount with a glass atomizer in gradient triangle patterns to investigate combinations of 3 and 4 different metals at a time. Samples can also be pipetted to form combinations of 4, 5, or 6 metals.
Figure 2: a) Signal averaged SMD data of iron oxide deposited via pipet. The applied bias was 0 V. b) The image on the right is actual student acquired data that shows a mixture of metals: zinc, copper and potassium. The standards iron oxide (upper left) and copper oxide (upper right). There was no applied bias.
Additionally, a recent collaboration has been established with Prof. Shannon Stahl at the University of Wisconsin Madison to using their method of detecting oxygen evolution via a fluorescent film (called HARPOON) with the combinations that we are investigating, with the hope of finding a potential water oxidation catalysts.
Interest III: Assessment development
For the past few years, I have been part of the a collaborative project that is a NSF-funded Mathematics and Science Partnership project entitled The Culturally Relevant Ecology, Learning Progressions and Environmental Literacy (NSF-0832173) establishing learning progressions for environmental science. The learning progressions span from 6th to 12th grade, studying the trajectory of learning that leads to the development of environmentally literate citizens capable of making informed decisions.
This project is a collaboration of six universities, four Long Term Ecological Research (LTER) Sites and LTER partner school districts. Research teams were established at partner universities (UW Oshkosh is included here) to lead efforts on study of three strands (i.e., carbon, water, and biodiversity) and three themes (i.e., quantitative reasoning, citizenship, and cultural relevance) within environmental literacy. I have specifically been involved with the quantitative reasoning (QR) research group as well as the water research group. We have been developing assessment items, interview protocols, and coding procedures while analyzing student data to create learning progressions based around these two areas. QR is of special interest due to the ever increasing need for problem solving citizenship.
While scientists have been investigating human impact on the environment for centuries, the need for quantitatively literate citizens who can make informed decisions about environmental issues has become imperative for those outside of the scientific community to understand how human impact within the local, regional, and global environments alter and shape environmental issues.