1. Anhui Univ, Inst Phys Sci & Informat Technol,Sch Mat Sci & En, Anhui Key Lab Informat Mat & Devices,Sch Phys & O, Minist Educ,Key Lab Struct & Funct Regulat Hybrid, Hefei 230601, Peoples R China
2. Civil Aviat Univ China, Ctr Aircraft Fire & Emergency, Dept Safety Engn, Tianjin 300300, Peoples R China
折叠
Abstract
Developing Pt-free counter electrodes (CEs) material for dye-sensitized solar cells (DSSCs) is significant. Herein, we fabricate a catalyst of Fe-N-C by employing N-doped hollow carbon flower (NHCF) as a matrix on which Fe-Nx coordination sites and Fe/Fe3C nanocrystals (Fe/Fe3C@NHCF) are mounted and coupled. The DSSC with Fe/Fe3C@NHCF CE achieves power conversion efficiency (PCE) of 9.37% and highly outperforms the one with Pt CE (7.77%). It is uncovered that Fe/Fe3C nanocrystals and Fe-Nx coordination sites generate a synergetic effect to enhance catalytic activity of the tri-iodide reduction reaction. The reasons are as follows: (1) Fe/Fe3C nanocrystals, which possess abundant interfaces and effectively promote the adsorption of reactants on the catalyst surface and charge transfer; (2) Atomically Fe-Nx configurations reduce charge density of Fe atomic centers and quicken reaction kinetics; (3) The unique structure of NHCF matrix almost utilizes all Fe/Fe3C nanocrystals, providing coupling bridge for nanocrystals with Fe-Nx sites.
Key words
Fe/Fe3C@NHCF/Electrocatalysis/Counter electrodes/Dye-sensitized solar cells
NSTL
Elsevier