Designing low-cost electrocatalysts combining the features of outstanding catalytic activity, excellent electrical conductivity, and high chemical stability remains a critical challenge for the large-scale fabrication of dye-sensitized solar cells (DSSCs). Here we report the controlled synthesis of CoS₂–CoSe₂ heterostructured nanocrystals encapsulated in N-doped carbon hollow nanocubes (CoS₂–CoSe₂@NC) through simultaneous sulfurization and selenization of polydopamine coated Prussian blue analogs. Benefiting from both structural and compositional characteristics, namely, the synergistic effect of CoS₂–CoSe₂ heterojunctions, the conductive N-doped carbon coating and the porous structure of the nanocubes, the resultant CoS₂–CoSe₂@NC nanocubes exhibit excellent electrocatalytic activity and cycling stability toward the generation of I₃⁻ ions in DSSCs. A typical device achieves a high power conversion efficiency (PCE) of 8.45% under AM1.5G illumination (100 mW cm⁻²), superior to that of a standard Pt-based device (8.07%). These results demonstrate that the as-synthesized CoS₂–CoSe₂@NC nanocubes are promising alternatives to Pt in DSSCs. The work represented here not only provides a promising strategy to design efficient and robust CE catalysts, but also can be extended for synthesizing other novel metal sulfide/selenide hybrid materials for applications in the fields of energy conversion and storage.

中文翻译：

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在N掺杂的碳纳米立方体中 封装CoS ₂ –CoSe ₂异质结构纳米晶体，作为染料敏化太阳能电池的高效对电极†

设计低成本电催化剂，兼具出色的催化活性，出色的电导率和高化学稳定性，仍然是大规模制造染料敏化太阳能电池（DSSC）的关键挑战。在这里，我们报告了通过同时硫化和硒化聚多巴胺涂覆的普鲁士蓝类似物的硒化，可控合成CoS ₂ -CoSe ₂异质结构纳米晶体，该结构包裹在N掺杂的碳空心纳米立方体中（CoS ₂ -CoSe ₂ @NC）。受益于结构和组成特征，即CoS ₂ -CoSe ₂的协同效应异质结，导电掺杂的N-碳涂层和纳米立方体的多孔结构，所得到的服务等级₂ -CoSe _2个@NC纳米立方体表现出对产生I优良的电催化活性和循环稳定性₃ ^-在DSSC中的离子。典型的设备在AM1.5G照明（100 mW cm ^-2）下可实现8.45％的高功率转换效率（PCE），优于标准的基于Pt的设备（8.07％）。这些结果表明，合成后的CoS ₂ -CoSe ₂@NC纳米立方体有望成为DSSC中Pt的替代品。此处代表的工作不仅为设计高效，耐用的CE催化剂提供了有前途的策略，而且可以扩展用于合成其他新型金属硫化物/硒化物杂化材料，用于能量转换和存储领域。