Metal sulfide nanostructures, which have been widely studied in recent years, are one of the most promising candidates in energy devices. Herein, coralloid hierarchical structures composed of Co₉S₈ hollow nanoneedle trunks and CuS nanosheet branches are, for the first time, well-constructed on fluorinated tin oxide (FTO) substrates via a multistep route. A seeding assistant strategy is applied to grow uniform and firm metal sulfide films on the FTO substrates. It is revealed that different seeds (i.e., TiO₂, CuS and ZnO) all have a positive effect to facilitate the film growth because of their surface roughening behavior on the FTO substrates. Significantly, such three dimensional (3D) Co₉S₈–CuS electrodes show superior electrocatalytic performance in the reduction reaction of polysulfide electrolyte, and yield an enhanced power conversion efficiency of 4.50% for CdS/CdSe quantum-dot sensitized solar cells as counter electrodes when compared with the one dimensional (1D) Co₉S₈ hollow nanoneedle (3.25%) and two dimensional (2D) CuS nanosheet (3.83%) electrodes. More impressively, the coralloid structure exhibits excellent stability in the electrochemical cycling tests, keeping 80% current after 500 cycles. Above all, the synthesis strategy here is also feasible to fabricate hybrid Co₉S₈–CuS films on various flexible substrates, such as carbon cloth, Ti mesh, and Ni foam for potential applications in wearable energy devices.

中文翻译：

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量子点敏化太阳能电池 的珊瑚状Co ₉ S ₈ –CuS分层结构的合理设计†

近年来已广泛研究的金属硫化物纳米结构是能源设备中最有前途的候选之一。在本文中，由Co ₉ S ₈空心纳米针主干和CuS纳米片分支组成的珊瑚层次结构首次通过多步路线在氟化氧化锡（FTO）基板上很好地构造。应用播种辅助策略在FTO基板上生长均匀且牢固的金属硫化物膜。结果表明，不同的种子（即TiO ₂，CuS和ZnO）都具有促进薄膜生长的积极作用，因为它们在FTO基板上的表面粗糙。值得注意的是，这样的三维（3D）Co ₉S ₈ -CuS电极在多硫化物电解质的还原反应中显示出优异的电催化性能，与一维（1D）Co相比，CdS / CdSe量子点敏化太阳能电池作为对电极产生的功率转换效率提高了4.50％₉ S ₈中空纳米针（3.25％）和二维（2D）CuS纳米片（3.83％）电极。更令人印象深刻的是，珊瑚状结构在电化学循环测试中表现出出色的稳定性，在500次循环后仍保持80％的电流。最重要的是，此处的合成策略对于制造混合Co ₉ S ₈也是可行的。–各种柔性基板上的CuS膜，例如碳布，Ti网眼和Ni泡沫，可在可穿戴能源设备中潜在应用。