Tribo- and contact electrification remain poorly understood, baffling and discombobulating scientists for millennia. Despite the technology needed to harvest mechanical energy with triboelectric generators being incredibly rudimentary and the fact that a triboelectric output can be obtained from almost any two material combinations, research into triboelectric generator materials typically focuses on achieving the highest possible output; meanwhile, understanding trends and triboelectric behaviours of related but lower performing materials is often overlooked or not studied. Metal–organic frameworks, a class of typically highly porous and crystalline coordination polymers are excellent media to study to fill this knowledge gap. Their chemistry, topology and morphology can be individually varied while keeping other material properties constant. Here we study 5 closely related zeolitic-imidazolate type metal–organic frameworks for their triboelectric performance and behaviour by contact-separating each one with five counter materials. We elucidate the triboelectric electron transfer behaviour of each material, develop a triboelectric series and characterise the surface potential by Kelvin-probe force microscopy. From our results we draw conclusions on how the chemistry, morphology and topology affect the triboelectric output by testing and characterising our series of frameworks to help better understand triboelectric phenomena.

中文翻译：

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选定沸石-咪唑酯骨架的摩擦电行为：探索化学、形态和拓扑影响


摩擦起电和接触起电仍然知之甚少，几千年来一直困扰着科学家。尽管用摩擦发电机收集机械能所需的技术非常初级，而且摩擦电输出几乎可以从任何两种材料组合中获得，但对摩擦发电机材料的研究通常侧重于实现尽可能高的输出；与此同时，对相关但性能较低的材料的趋势和摩擦电行为的理解常常被忽视或没有研究。金属有机框架是一类典型的高度多孔和结晶配位聚合物，是填补这一知识空白的优秀研究介质。它们的化学、拓扑和形态可以单独改变，同时保持其他材料特性不变。在这里，我们通过将每种材料与五种相反材料接触分离，研究了 5 种密切相关的沸石-咪唑盐型金属有机框架的摩擦电性能和行为。我们阐明了每种材料的摩擦电电子转移行为，开发了摩擦电系列并通过开尔文探针力显微镜表征了表面电势。根据我们的结果，我们通过测试和表征我们的一系列框架，得出化学、形态和拓扑如何影响摩擦电输出的结论，以帮助更好地理解摩擦电现象。