title: Highly electrocatalytic activity of RuO₂ nanocrystals for triiodide reduction in dye-sensitized solar cells.
abstract: Dye-sensitized solar cells (DSCs) are promising alternatives to conventional silicon devices because of their simple fabrication procedure, low cost, and high efficiency. Platinum is generally used as a superior counter electrode (CE) material, but the disadvantages such as high cost and low abundance greatly restrict the large-scale application of DSCs. An efficient and sustainable way to overcome the limited supply of Pt is the development of high-efficiency Pt-free CE materials, which should possess both high electrical conductivity and superior electrocatalytic activity simultaneously. Herein, for the first time, a two-step strategy to synthesize ruthenium dioxide (RuO₂) nanocrystals is reported, and it is shown that RuO₂ catalysts exhibit promising electrocatalytic activity towards triiodide reduction, which results in comparable energy conversion efficiency to that of conventional Pt CEs. More importantly, by virtue of first-principles calculations, the catalytic mechanism of electrocatalysis for triiodide reduction on various CEs is investigated systematically and it is found that the electrochemical triiodide reduction reaction on RuO₂ catalyst surfaces can be enhanced significantly, owing to the ideal combination of good electrocatalytic activity and high electrical conductivity.
authors.affiliation: Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Hou
authors.forename: Zu Peng
authors.initials: ZP
authors.lastname: Chen
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Shuang
authors.initials: S
authors.lastname: Yang
authors.forename: Hai Feng
authors.initials: HF
authors.lastname: Wang
authors.forename: P
authors.initials: P
authors.lastname: Hu
authors.forename: Hui Jun
authors.initials: HJ
authors.lastname: Zhao
authors.forename: Hua Gui
authors.initials: HG
authors.lastname: Yang
keywords: counter electrodes; density functional calculations; nanocrystalline materials; ruthenium; solar cells