title: Electrocatalytic activity of NiO on silicon nanowires with a carbon shell and its application in dye-sensitized solar cell counter electrodes.
abstract: To improve the catalytic activity of a material, it is critical to maximize the effective surface area by directly contacting the electrolyte. Nanowires are a promising building block for catalysts in electrochemical applications because of their large surface area. Nickel oxide (NiO) decoration was achieved by drop-casting a nickel-dissolved solution onto vertically aligned silicon nanowire arrays with a carbon shell (SiNW/C). Based on the hybridization of the NiO and silicon nanowire arrays with a carbon shell this study aimed to achieve a synergic effect for the catalytic activity performance. This study demonstrated that the resulting nanomaterial exhibits excellent electrocatalytic activity and performs well as a counter electrode for dye-sensitized solar cells (DSSCs). The compositions of the materials were examined using X-ray diffraction, X-ray photoelectron spectroscopy, and energy dispersive spectroscopy. Their micro- and nano-structures were investigated using scanning electron microscopy and transmission electron microscopy. The electrochemical activity toward I(-)/I3(-) was examined using cyclic voltammetry and electrochemical impedance spectroscopy. The obtained peak power conversion efficiency of the DSSC based on the NiO@SiNW/C counter electrode was 9.49%, which was greater than that of the DSSC based on the Pt counter electrode.
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 137-713, Korea. donghwan@korea.ac.kr.
authors.forename: Junhee
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Chemical Engineering, UNIST, Banyeon, Ulju, Ulsan 689-798, Korea.
authors.forename: Cho-long
authors.initials: CL
authors.lastname: Jung
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 137-713, Korea. donghwan@korea.ac.kr.
authors.forename: Minsoo
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 137-713, Korea. donghwan@korea.ac.kr.
authors.forename: Soomin
authors.initials: S
authors.lastname: Kim
authors.affiliation: KU KIST Green School, Korea University, Anam-dong, Seongbuk-gu, Seoul 137-713, Korea.
authors.forename: Yoonmook
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 137-713, Korea. donghwan@korea.ac.kr.
authors.forename: Hae-seok
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Korea University, Jochiwon 339-700, Korea.
authors.forename: Jeounghee
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Materials Chemistry and Engineering, Konkuk University, Hwayang, Gwangjin, Seoul 143-701, Korea. yjun@konkuk.ac.kr.
authors.forename: Yongseok
authors.initials: Y
authors.lastname: Jun
authors.affiliation: Department of Materials Science and Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 137-713, Korea. donghwan@korea.ac.kr.
authors.forename: Donghwan
authors.initials: D
authors.lastname: Kim