The integration of dye-sensitized solar cells (DSSCs) with building roof panels, windows, and various decorative outdoor installations is presently an important research topic for their immediate commercialization potential because of their power generation capability, sustainability, and aesthetic appearance. For industrial applications, Pt counter electrodes (CEs) need to be replaced with Pt-free CEs because of their limited sources and cost. An ideal CE should be economical, abundant, and have excellent electrochemical stability and activity, with easy processing in bulk. As an alternative practical CE, we introduce for the first time a carbon nano-onion (CNO)-based CE for transparent DSSCs. We developed a simple, energy-efficient one-step synthesis technique for fabricating high-quality CNOs in bulk quantities without any sophisticated instrumentation and expensive nanodiamond precursors. CNO CEs proved to be promising in terms of optical transparency, reasonable electrochemical redox activity for the I⁻/I₃⁻ redox couple, and exchange current density comparable to Pt CEs. CNO-powered DSSCs demonstrated an optical transparency of >55% with a significant solar energy conversion efficiency of 5.17%. The intrinsic hydrophilicity of the as-synthesized CNO eliminates the use of a binder or an additive, unlike in the case of other carbon allotropes. Our results demonstrate the possibility of using CNO-based CEs as promising substitutes for scarce and expensive Pt-based CEs for low-cost DSSCs.

中文翻译：

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碳纳米洋葱供电的光学透明且经济的染料敏化太阳能电池。

染料敏化太阳能电池（DSSC）与建筑顶板，窗户和各种户外装饰装置的集成，由于其发电能力，可持续性和美观性，目前对于其即时商业化潜力是一个重要的研究课题。对于工业应用，由于其有限的来源和成本，需要用无Pt的CE替换Pt对电极（CE）。理想的CE应该经济，丰富，并具有出色的电化学稳定性和活性，并且易于批量加工。作为替代性实用CE，我们首次引入了基于碳纳米洋葱（CNO）的CE用于透明DSSC。我们开发了一个简单的 高效的一步合成技术，无需大量精密仪器和昂贵的纳米金刚石前驱体即可批量生产高质量CNO。CNO CEs在光学透明性，I的合理电化学氧化还原活性方面被证明是有前途的^- / I ₃ ^-氧化还原电对和交换电流密度堪比铂的CE。由CNO供电的DSSC表现出大于55％的光学透明度，并且具有5.17％的显着太阳能转化效率。与其他碳同素异形体不同，合成后的CNO固有的亲水性消除了粘合剂或添加剂的使用。我们的结果表明，使用基于CNO的CE作为低成本DSSC稀缺且昂贵的基于Pt的CE的有希望的替代品的可能性。