abs

학술발표회초록보기

초록문의 abstract@kcsnet.or.kr

결제문의 member@kcsnet.or.kr

현재 가능한 작업은 아래와 같습니다.
  • 03월 08일 23시 이후 : 초록수정 불가능, 일정확인 및 검색만 가능

제127회 대한화학회 학술발표회 및 총회 Electrochemical Monitoring and Mechanistic Understanding of Iodine Film Formation as a Metastable Intermediate during I3−/I− Redox Reaction in Aqueous ZnI2 Media

등록일
2021년 2월 16일 15시 59분 46초
접수번호
0294
발표코드
ELEC1-3 이곳을 클릭하시면 발표코드에 대한 설명을 보실 수 있습니다.
발표시간
목 14시 : 10분
발표형식
심포지엄
발표분야
Electrochemistry - New Horizons for Molecular Electrochemistry and Its Applications
저자 및
공동저자
Jinho Chang
Department of Chemistry, Hanyang University, Korea
Zn-polyiodide redox flow batteries (RFBs) are a promising grid-scale electrical energy storage (EES) option because of their significant energy density, which is due to the high solubility of ZnI2 in water. In spite of the importance of the RFBs, a mechanistic understanding of both Zn2+/Zn and I3−/I− half redox reactions have not been fully achieved yet. The I3−/I− half redox reaction occurring on a cathode in this RFB is particularly complicated due to metastable iodine films, which only form on an electrode when an electrochemical potential is biased enough to drive the electro-oxidation of I−. Due to the thermodynamically unstable nature of iodine films in I−-rich aqueous solutions, the film is also difficult to characterize by ex-situ analyses, and its physicochemical properties are largely unknown. In this article, we report electrochemical in situ monitoring of the formation and dissolution of a metastable iodine film as an intermediate during I3−/I− redox reactions in an aqueous solution using a rotating ring disk electrode (RRDE). We suggested a reaction model for electro-oxidation of I− to I3− via iodine films and its electro-reduction to I− based on the mechanism proposed by Gileadi et al. Chronoamperograms (CAs) and cyclic voltammograms (CVs) associated with the I2/I− redox reaction involving only formation and dissolution of iodine films on a disk electrode were obtained using an RRDE. From the CAs and CVs, we successfully obtained trajectory information on the formation and dissolution of an iodine film during the I3−/I− redox reaction on a disk electrode under transient and potential-time variation conditions. In addition, we found evidence of a possible transition in the iodine film from an I−-conductor to an I−-semiconductor during formation based on the quantitatively monitored iodine formation curve as a function of time during electro-oxidation of I−.

상단으로