Accession Number:

ADA581674

Title:

Sulfur Dioxide and Nitrogen Dioxide Adsorption on Zinc Oxide and Zirconium Hydroxide Nanoparticles and the Effect on Photoluminescence

Descriptive Note:

Journal article

Corporate Author:

MASSACHUSETTS UNIV LOWELL

Personal Author(s):

• Im, Jisun
• Peterson, Gregory W.
• Whitten, James E.
• Singh, Jagdeep
• Mukherjee, Anupama
• Sengupta, Sandip K.

Report Date:

2012-01-01

Pagination or Media Count:

11.0

Abstract:

Nanoparticulate zinc oxide and micron-size zirconium hydroxide powders have been exposed to sulfur dioxide and nitrogen dioxide by flowing the gases, diluted with nitrogen, over powder samples. X-ray photoelectron spectroscopy XPS, Raman spectroscopy, and thermal gravimetric analyses TGA indicate strongly bound, chemisorbed SO3 and NO3 surface species. Two pre-treatments of the nanoparticulate ZnO samples prior to gas exposure have been investigated 1 drying overnight in a vacuum oven and 2 hydrating the samples by placing them overnight in water-saturated air. A dramatic difference in reactivity of ZnO is observed, with approximately two-fold and ten-fold greater uptake of NO2 and SO2, respectively, measured by XPS for the hydrated samples relative to the dried ones. Transmission electron microscopy TEM demonstrates that the greater uptake arises from a morphology change in the case of the hydrated samples, and it is postulated that this is due to dissolution of the gases in physisorbed water, which leads to acids that partially erode the ZnO and lead to greater surface area. For zirconium hydroxide, no morphology change is observed for hydrated samples, and SO4 ads, in addition to SO3 ads, is indicated by XPS. ZnO and ZrOH4 both exhibit photoluminescence PL spectra, with peak intensities that change dramatically due to hydration and subsequent exposure to SO2 and NO2 gases. Dosing of the powders with these gases effectively reverts the PL spectra to those corresponding to less hydration.

Descriptors:

• *PHOTOELECTRON SPECTRA
• *PHOTOLUMINESCENCE
• ADSORPTION
• DETECTORS
• DILUTION
• DIOXIDES
• ELECTRON MICROSCOPY
• GASES
• GRAVIMETRIC ANALYSIS
• HYDRATION
• HYDROXIDES
• INTENSITY
• MORPHOLOGY
• NITROGEN DIOXIDE
• OXIDES
• PEAK VALUES
• POWDERS
• RAMAN SPECTROSCOPY
• REACTIVITIES
• REPRINTS
• SAMPLING
• SPECTRA
• SULFUR OXIDES
• THERMAL ANALYSIS
• VACUUM
• X RAYS
• ZINC OXIDES
• ZIRCONIUM

Subject Categories:

• Inorganic Chemistry
• Optics
• Nuclear Physics and Elementary Particle Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE