3D hierarchical FeSe2 microspheres: Controlled synthesis and applications in dye-sensitized solar cells. (July 2015)

• Record Type: Journal Article
• Authors: Huang, Shoushuang; He, Qingquan; Chen, Wenlong; Zai, Jiantao; Qiao, Qiquan; Qian, Xuefeng
• Is Part Of: Nano energy. Volume 15(2015:Jul.)
• Page Start: 205
• Page End: 215
• Publication Date: 2015-07
• Subjects: FeSe2 -- Counter electrode -- Diselenide -- Hierarchical microspheres -- Dye-sensitized solar cells; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2015.04.027
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Mastery over the structures at nano/microscale can effectively tailor the catalytic activity and durability of materials. Herein, three dimension (3D) hierarchical iron diselenide (FeSe2 ) microspheres have been successfully synthesized via a hot-injection method. The morphologies of building blocks and final products can be simply controlled by the amount and/or the type of alkythiols, from irregular micro/nanoparticles to uniform 3D hierarchical microspheres made of ultrathin nanosheets or rhombus-like nanorods. A formation mechanism has been understood based on the inherent crystal structure of FeSe2 and the selective adsorption of alkythiols. The as-obtained FeSe2 samples were employed as counter electrode (CE) materials in dye-sensitized solar cells (DSSCs). Electrochemical characterizations indicated that the 3D hierarchical FeSe2 microspheres composed of ultrathin nanosheets (FeSe2 NSs) exhibited low charge transfer resistance at the electrolyte–electrode interface, high electrocatalytic activity and fast reaction kinetics for the I − /I3 − redox reaction. A DSSC with FeSe2 NSs CE achieved a high power conversion efficiency of 8.39% under a simulated solar illumination of 100 mW cm −2 (AM 1.5), comparable to that of Pt based devices (8.20%). Moreover, the fast activity onset and relatively long stability demonstrated that the FeSe2 NSs is a promising alternative to Pt in DSSC. Graphical abstract: Highlights: 3D FeSe2 microspheres were controlled synthesized by selective adsorption of alkythiols though hot-injection method. 3D FeSe2 microspheres constructed by ultrathin 2D nanosheets can provide abundant active sites and facilitate the diffusion of electrolyte, exhibiting comparable catalytic activity to Pt. The FeSe2 NSs CE exhibited better stable capability than Pt toward iodine-based electrolyte.