東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Linked to FindBook

Google Book

Amazon

博客來

Photochemical and Photophysical Dynamics of the Aqueous Ferrate(VI) Ion.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Photochemical and Photophysical Dynamics of the Aqueous Ferrate(VI) Ion./
Author:	Antolini, Cali.
Description:	1 online resource (152 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 84-11, Section: B.
Contained By:	Dissertations Abstracts International84-11B.
Subject:	Chemistry. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=30417713click for full text (PQDT)
ISBN:	9798379501006

Photochemical and Photophysical Dynamics of the Aqueous Ferrate(VI) Ion.
Antolini, Cali.

Photochemical and Photophysical Dynamics of the Aqueous Ferrate(VI) Ion. - 1 online resource (152 pages)

Source: Dissertations Abstracts International, Volume: 84-11, Section: B.

Thesis (Ph.D.)--University of Rhode Island, 2023.

Includes bibliographical references

Ferrate(VI) has been suggested as a 'green' alternative to current oxidation and disinfection methods used in water treatment, especially in combination with ultraviolet light. UV-activation of the ferrate salts has been shown to improve the efficiency of treating water due to the generation of highly oxidizing Fe(V) and Fe(IV) species. However, the incomplete understanding behind the nature of these intermediates, the mechanisms by which they form, and their roles in downstream oxidation reactions have limited the full-scale use of ferrate salts in facilities. Our goal is to advance the engineering of UV/ferrate(VI)-based water treatment processes by gaining a better understanding of the photochemistry and photophysics of the aqueous ion through optical and X-ray transient absorption spectroscopy. We used multi-wavelength pump-probe techniques to observe branching between relaxation into the metal-centered triplet Fe(VI) states and intersystem crossing to the quintet LMCT state. We further examined the excited state dynamics related to the 3MC states without interference from charge transfer states through visible pump experiments. A quantum yield of 15% was found for the formation of a reduced iron species, which is believed to be the primary reactive species in UV-activated water oxidation with ferrate(VI). This finding was confirmed using iron K-edge transient absorption spectroscopy. To further investigate the mechanism, experiments were repeated in a deuterated buffer solution. We found a tenfold increase in the lifetime of the 3MC states in comparison to the aqueous buffer following photoexcitation, which we attributed to the mismatch in vibrational quanta needed to span the energy gap between the 3A2 and 3T2 metal-centered transition. We further investigated the ferrate(VI) ion structure and dynamics using X-ray emission spectroscopy.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2023

Mode of access: World Wide Web

ISBN: 9798379501006Subjects--Topical Terms:

516420
Chemistry.
Subjects--Index Terms:

FerrateIndex Terms--Genre/Form:

542853
Electronic books.

Photochemical and Photophysical Dynamics of the Aqueous Ferrate(VI) Ion.
LDR:03266nmm a2200397K 4500 001 2360754
005 20231015184514.5
006 m o d
007 cr mn ---uuuuu
008 241011s2023 xx obm 000 0 eng d
020 $a 9798379501006
035 $a (MiAaPQ)AAI30417713
035 $a AAI30417713
040 $a MiAaPQ $b eng $c MiAaPQ $d NTU
100 1 $a Antolini, Cali. $3 3701385
245 1 0 $a Photochemical and Photophysical Dynamics of the Aqueous Ferrate(VI) Ion.
264 0 $c 2023
300 $a 1 online resource (152 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 84-11, Section: B.
500 $a Advisor: Hayes, Dugan.
502 $a Thesis (Ph.D.)--University of Rhode Island, 2023.
504 $a Includes bibliographical references
520 $a Ferrate(VI) has been suggested as a 'green' alternative to current oxidation and disinfection methods used in water treatment, especially in combination with ultraviolet light. UV-activation of the ferrate salts has been shown to improve the efficiency of treating water due to the generation of highly oxidizing Fe(V) and Fe(IV) species. However, the incomplete understanding behind the nature of these intermediates, the mechanisms by which they form, and their roles in downstream oxidation reactions have limited the full-scale use of ferrate salts in facilities. Our goal is to advance the engineering of UV/ferrate(VI)-based water treatment processes by gaining a better understanding of the photochemistry and photophysics of the aqueous ion through optical and X-ray transient absorption spectroscopy. We used multi-wavelength pump-probe techniques to observe branching between relaxation into the metal-centered triplet Fe(VI) states and intersystem crossing to the quintet LMCT state. We further examined the excited state dynamics related to the 3MC states without interference from charge transfer states through visible pump experiments. A quantum yield of 15% was found for the formation of a reduced iron species, which is believed to be the primary reactive species in UV-activated water oxidation with ferrate(VI). This finding was confirmed using iron K-edge transient absorption spectroscopy. To further investigate the mechanism, experiments were repeated in a deuterated buffer solution. We found a tenfold increase in the lifetime of the 3MC states in comparison to the aqueous buffer following photoexcitation, which we attributed to the mismatch in vibrational quanta needed to span the energy gap between the 3A2 and 3T2 metal-centered transition. We further investigated the ferrate(VI) ion structure and dynamics using X-ray emission spectroscopy.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2023
538 $a Mode of access: World Wide Web
650 4 $a Chemistry. $3 516420
650 4 $a Physical chemistry. $3 1981412
650 4 $a Analytical chemistry. $3 3168300
653 $a Ferrate
653 $a Ultrafast spectroscopy
653 $a X-ray absorption spectroscopy
653 $a X-ray emission spectroscopy
653 $a Photochemistry
655 7 $a Electronic books. $2 lcsh $3 542853
690 $a 0485
690 $a 0486
690 $a 0494
710 2 $a ProQuest Information and Learning Co. $3 783688
710 2 $a University of Rhode Island. $b Chemistry. $3 2096060
773 0 $t Dissertations Abstracts International $g 84-11B.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=30417713 $z click for full text (PQDT)