Narrow-Bandgap Chalcogenoviologens for Electrochromism and Visible-Light-Driven Hydrogen Evolution

Guoping Li; Letian Xu; Weidong Zhang; Kun Zhou; Yousong Ding; Fenglin Liu; Xiaoming He; Gang He

doi:10.1002/anie.201711761

Narrow-Bandgap Chalcogenoviologens for Electrochromism and Visible-Light-Driven Hydrogen Evolution

Angew Chem Int Ed Engl. 2018 Apr 23;57(18):4897-4901. doi: 10.1002/anie.201711761. Epub 2018 Mar 26.

Authors

Guoping Li¹, Letian Xu¹, Weidong Zhang¹, Kun Zhou¹, Yousong Ding¹, Fenglin Liu¹, Xiaoming He², Gang He¹

Affiliations

¹ Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi Province, 710054, China.
² School of Chemical Science and Engineering, Tongji University, Shanghai, 200092, China.

PMID: 29489048
DOI: 10.1002/anie.201711761

Abstract

A series of electron-accepting chalcogen-bridged viologens with narrow HOMO-LUMO bandgaps and low LUMO levels is reported. The optoelectronic properties of chalcogenoviologens can be readily tuned through heavy atom substitution (S, Se and Te). Herein, in situ electrochemical spectroscopy was performed on the proof-of-concept electrochromic devices (ECD). E-BnV²⁺ (E=Se, Te; BnV²⁺ =benzyl viologen) was used for the visible-light-driven hydrogen evolution due to the strong visible-light absorption. Remarkably, E-BnV²⁺ was not only used as a photosensitizer, but also as an electron mediator, providing a new strategy to explore photocatalysts. The higher apparent quantum yield of Se-BnV²⁺ could be interpreted in terms of different energy levels, faster electron-transfer rates and faster formation of radical species.

Keywords: chalcogens; electrochemistry; electrochromism; hydrogen evolution; viologens.

Publication types

Research Support, Non-U.S. Gov't