eprintid: 17251 rev_number: 22 userid: 1419 dir: disk0/00/01/72/51 datestamp: 2013-02-08 20:50:36 lastmod: 2021-06-13 02:55:17 status_changed: 2013-02-08 20:50:36 type: article metadata_visibility: show item_issues_count: 0 eprint_status: archive creators_name: Asher, SA creators_name: Tuschel, DD creators_name: Vargson, TA creators_name: Wang, L creators_name: Geib, SJ creators_email: asher@pitt.edu creators_email: creators_email: creators_email: creators_email: geib@pitt.edu creators_id: ASHER creators_id: creators_id: creators_id: creators_id: GEIB creators_orcid: creators_orcid: creators_orcid: creators_orcid: creators_orcid: 0000-0002-9160-7857 title: Solid state and solution nitrate photochemistry: Photochemical evolution of the solid state lattice ispublished: pub divisions: sch_as_chemistry full_text_status: public abstract: We examined the deep UV 229 nm photochemistry of NaNO3 in solution and in the solid state. In aqueous solution excitation within the deep UV NO3- strong π → π* transition causes the photochemical reaction NO3- → NO2- + O·. We used UV resonance Raman spectroscopy to examine the photon dose dependence of the NO2- band intensities and measure a photochemical quantum yield of 0.04 at pH 6.5. We also examined the response of solid NaNO3 samples to 229 nm excitation and also observe formation of NO2-. The quantum yield is much smaller at ∼10-8. The solid state NaNO3 photochemistry phenomena appear complex by showing a significant dependence on the UV excitation flux and dose. At low flux/dose conditions NO2- resonance Raman bands appear, accompanied by perturbed NO3- bands, indicating stress in the NaNO3 lattice. Higher flux/dose conditions show less lattice perturbation but SEM shows surface eruptions that alleviate the stress induced by the photochemistry. Higher flux/dose measurements cause cratering and destruction of the NaNO3 surface as the surface layers are converted to NO2-. Modest laser excitation UV beams excavate surface layers in the solid NaNO3 samples. At the lowest incident fluxes a pressure buildup competes with effusion to reach a steady state giving rise to perturbed NO3- bands. Increased fluxes result in pressures that cause the sample to erupt, relieving the pressure. © 2011 American Chemical Society. date: 2011-05-05 date_type: published publication: Journal of Physical Chemistry A volume: 115 number: 17 pagerange: 4279 - 4287 refereed: TRUE issn: 1089-5639 id_number: 10.1021/jp200406q pmid: 21462986 mesh_headings: Nitrates--chemistry mesh_headings: Photochemistry mesh_headings: Solutions mesh_headings: Spectrum Analysis, Raman mesh_headings: Ultraviolet Rays chemical_names: Nitrates chemical_names: Solutions chemical_names: sodium nitrate citation: Asher, SA and Tuschel, DD and Vargson, TA and Wang, L and Geib, SJ (2011) Solid state and solution nitrate photochemistry: Photochemical evolution of the solid state lattice. Journal of Physical Chemistry A, 115 (17). 4279 - 4287. ISSN 1089-5639 document_url: http://d-scholarship-dev.library.pitt.edu/17251/1/licence.txt