Environmental Stimuli‐Irresponsive Long‐Term Radical Scavenging of 2D Transition Metal Dichalcogenides through Defect‐Mediated Hydrogen Atom Transfer in Aqueous Media

• Published in: Advanced functional materials Vol. 28; no. 44
• Main Authors: Kim, Ji Eun, Yim, DaBin, Lee, Chi Ho, Jun, Byeongsun, Nam, Jin, Han, Sang Hoon, Lee, Sang Uck, Kim, Jong‐Ho, Kim, Jin Woong
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 31.10.2018
• Subjects: amphiphilic block copolymers; Chalcogenides; Dispersion; Ethylene oxide; Hydrogen; Hydrogen atoms; Hydrogen storage; hydrogen transfer; Materials science; Molybdenum disulfide; Nanostructure; radical scavenging; Scavenging; Transition metal compounds; transition metal dichalcogenide nanosheets
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201802737

A transition metal dichalcogenide (TMD) based antioxidation platform is proposed, in which radical scavenging is accomplished by the defect‐mediated one‐step hydrogen atom transfer (HAT) occurring on the nanosheets in water. To this end, the TMD nanosheets, including MoS2, WS2, MoSe2, and WSe2, are finely dispersed in water with the aid of an amphiphilic poly(ε‐caprolactone)‐b‐poly(ethylene oxide) (PCL‐b‐PEO) diblock copolymer that envelops the nanosheets with a molecular layer of less than 1 nm thickness. It is then demonstrated that the PCL‐b‐PEO‐stabilized TMD nanosheets show the extraordinarily enhanced and prolonged radical scavenging activity in water even under harsh storage conditions. Theoretical modeling studies on HAT suggest that more favorable hydrogen association from chalcogen vacancies on the nanosheets dispersed in water can lead to the easier dissociation of hydrogen atoms with exothermicity by −0.43 to −1.33 eV, thus exhibiting such an outstanding radical scavenging performance. A transition metal dichalcogenide (TMD) based antioxidation platform is proposed. It is shown that radical scavenging is accomplished by defect‐mediated one‐step hydrogen atom transfer occurring on the TMD nanosheets stably dispersed in water. Taking advantage of this, it is demonstrated that the TMD nanosheets enveloped with a molecular layer of amphiphilic poly(ε‐caprolactone)‐b‐poly(ethylene oxide) can be used as promising radical scavengers.