染料敏化太阳能电池碳基对电极的研究进展

Carbon-based Counter Electrodes for Dye-sensitized Solar Cells:State-of-art Progress,Challenges and Perspectives

作为第3代新型薄膜太阳能电池的代表之一,染料敏化太阳能电池(DSSCs)是近年来光伏领域的一个研究热点。对电极是DSSCs的一个关键组成部分,其功能是收集来自外电路的电子并实现电解质中I^(-)_(3)的催化还原。通常,DSSCs的对电极为贵金属铂(Pt),但Pt的储量有限、价格高昂、在电化学环境中稳定性差,这些缺点很大程度上增加了DSSCs的成本并限制了其规模化应用。开发廉价、高效、稳定性好的对电极材料,是克服这些瓶颈性难题的有效对策。碳材料具有低成本、高导电性和良好稳定性等优点,有望取代昂贵的Pt对电极。介绍近年来碳基对电极的研究进展,包括多孔碳、碳纳米纤维、碳纳米管、石墨烯、石墨炔和MOF衍生碳等材料,分析比较各种功能碳材料的结构特点,详述其制备方法;归纳总结碳材料的原子/电子性质、限域结构、表界面物性、缺陷位等对质量传递、电荷传递、电催化活性的调变规律。最后,展望了功能碳材料对电极现存的问题及未来发展的方向。

As one representative of the third-generation solar cells,dye-sensitized solar cells(DSSCs)have attracted great interests in the photovoltaic field.Counter electrode(CE)is one of crucial components in DSSCs,which functions as the collector of electrons from the external circuit and catalyzing the reduction of I^(-)_(3).In general,platinum(Pt)metal is commonly used as the CE of DSSCs,which has disadvantages including the limited reserves,the high cost,and the electrochemical instability,resulting in the high cost of DSSCs and limited applications in large scale.As such,it is urgent to develop counter electrode materials with low price,high efficiency,and good stability.Carbon materials with low cost,high conductivity and good stability have shown great potential to supersede the noble Pt.In this review,recent research progress of carbon-based CEs in DSSCs is summarized in detail,including porous carbon,carbon nanofibers,carbon nanotubes,graphene,graphdiyne and MOF-derived carbon.The structural characteristics and the preparation methods of various functional carbon catalysts are analyzed and compared.The regulation of the properties of carbon materials(e.g.,the atomic/electronic properties,the confined structures,the surface/interface properties,and the defects)on the mass transfer,charge transfer,and corresponding electrocatalytic activities have been addressed in detail.Finally,the challenges and the perspectives of carbon-based CEs are outlined.