Porous, Platinum Nanoparticle-Adsorbed Carbon Nanotube Yarns for Efficient Fiber Solar Cells

Abstract

Pt is a classical catalyst that has been extensively used in fuel cell and solar cell electrodes, owing to its high catalytic activity, good conductivity, and stability. In conventional fiber-shaped solar cells, solid Pt wires are usually adopted as the electrode material. Here, we report a Pt nanoparticle-adsorbed carbon nanotube yarn made by solution adsorption and yarn spinning processes, with uniformly dispersed Pt nanoparticles through the porous nanotube network. We have fabricated TiO(2)-based dye-sensitized fiber solar cells with a Pt-nanotube hybrid yarn as counter electrode and achieved a power conversion efficiency of 4.85% under standard illumination (AM1.5, 100 mW/cm(2)), comparable to the same type of fiber cells with a Pt wire electrode (4.23%). Adsorption of Pt nanoparticles within a porous nanotube yarn results in enhanced Pt-electrolyte interfacial area and significantly reduced charge-transfer resistance across the electrolyte interface, compared to a pure nanotube yarn or Pt wire. Our porous Pt-nanotube hybrid yarns have the potential to reduce the use of noble metals, lower the device weight, and improve the solar cell efficiency.

Tailoring the efficiency of 3D wire-shaped photovoltaic cells (WPVCs) by functionalization of solid-liquid interfacial properties

“…To avoid these reverse catalytic effects and further improve the cell performance, platinized CNYs were introduced to the WPVC as a replacement of conventional CEs. CNYs with Pt nanoparticles become functional to enrich the reciprocity between electrolyte and Pt particles by decreasing resistance of charge-transfer [47]. The cells with platinized CNYs enhance the J sc from 0.57 to 1.24 mA cm À2 (a 218% improvement) (Fig.…”

“…Furthermore, the conventional metal microwire shaped CEs (Pt, Ag wire, etc) are costly and easily corroded by liquid electrolytes [44][45][46]. However, the WPVC with virgin CNY (CEs) has adverse catalytic effects on the redox mediator (I À /I 3 À ), which allows light-generated electrons to react with I À 3 in the electrolyte [16,47]. To avoid these reverse catalytic effects and further improve the cell performance, platinized CNYs were introduced to the WPVC as a replacement of conventional CEs.…”

Development of carbon nanotube/copper composite yarn by electrodeposition and evaluation of ampacity

“…sp2 結合で連なった一次元物質であり，金属材料の約 1000 倍の大電流容量を示すことから大電流容量配線の基材 としての利用が期待されている (Collins et al, 2001, Wei et al, 2001, Yao et al, 2000．CNT の成長限界は数 mm であ り配線材料としての利用には長尺化が課題となっていたが，近年では CNT を紡績して糸にする技術が開発され ている (Jiang et al, 2002, Dalton et al, 2003, Li et al, 2004．CNT 糸は気相成長法によって基板上に垂直成長させた 無数の CNT（CNT フォレスト）から連続的に紡績することが可能である．垂直成長 CNT はファンデルワールス 力によって隣接する CNT 同士で連なり CNT 糸を形成する．CNT 糸の紡績方法の開発によって CNT の長尺化の 問題が解消される一方で， CNT 糸は CNT 同士の接触点や各 CNT 端部のダングリングボンドの存在により抵抗率 が高く，CNT 単体と比較して電気特性が著しく低いことが課題となる (Zhong et al, 2010．CNT の 長尺化と電気特性の両立は困難であるが，CNT 単体を数 m オーダーに成長させることが現状不可能であるのに 対し， CNT 糸の電気特性を向上させる方法はいくつか存在し CNT 糸を基材として大電流容量 CNT 配線を創製で きると考えられる． CNT 糸などの CNT 集合体の電気特性の向上方法の一つとして，導電性の付与を目的に金属や金属酸化物との 複合化が行われている (Zhan et al, 2003, Ganguli et al, 2013, Zhang et al, 2014, Zhang et al, 2012, Jiang et al, 2015 …”

Synthesis of Single-Walled Carbon Nanotube−Nanoparticle Hybrid Structures

“…SWNT-nanoparticle hybrids synthesized by noncovalent coordination interactions have shown promising applications in optoelectronic devices (12,30,31), catalysis (32)(33)(34)(35), solar cells (36), cancer therapy (37) and composite materials (6). In general, SWNTs sidewalls can be noncovalently functionalized with metal nanoparticles synthesized by solution-reduction methods and linked via aromatic compounds, surfactants, and polymers, which employ π-π stacking interactions.…”

“…A Pt-nanoparticleadsorbed carbon nanotube yarn made by solution adsorption and yarn spinning processes was synthesized and used as the counter electrode in a TiO 2 -based dye-sensitized fiber solar cell (36). Pt nanoparticles were first synthesized via the reduction of H 2 PtCl 6 by ethylene glycol.…”