Tonelli Domenica, Gualandi Isacco, Musella Elisa, Scavetta Erika
Department of Industrial Chemistry "Toso Montanari", University of Bologna, Viale Risorgimento 4, 40136 Bologna, Italy.
Nanomaterials (Basel). 2021 Mar 13;11(3):725. doi: 10.3390/nano11030725.
Layered double hydroxides (LDHs) are anionic clays which have found applications in a wide range of fields, including electrochemistry. In such a case, to display good performances they should possess electrical conductivity which can be ensured by the presence of metals able to give reversible redox reactions in a proper potential window. The metal centers can act as redox mediators to catalyze reactions for which the required overpotential is too high, and this is a key aspect for the development of processes and devices where the control of charge transfer reactions plays an important role. In order to act as redox mediator, a material can be present in solution or supported on a conductive support. The most commonly used methods to synthesize LDHs, referring both to bulk synthesis and in situ growth methods, which allow for the direct modification of conductive supports, are here summarized. In addition, the most widely used techniques to characterize the LDHs structure and morphology are also reported, since their electrochemical performance is strictly related to these features. Finally, some electrocatalytic applications of LDHs, when synthesized as nanomaterials, are discussed considering those related to sensing, oxygen evolution reaction, and other energy issues.
层状双氢氧化物（LDHs）是一类阴离子型黏土，已在包括电化学在内的广泛领域得到应用。在这种情况下，为了展现出良好的性能，它们应具备导电性，而这可以通过存在能够在合适的电位窗口内发生可逆氧化还原反应的金属来确保。金属中心可以作为氧化还原介质来催化那些所需过电位过高的反应，这对于电荷转移反应控制起着重要作用的工艺和器件的开发而言是一个关键方面。为了充当氧化还原介质，一种材料可以存在于溶液中或负载在导电载体上。本文总结了合成LDHs最常用的方法，包括本体合成法和原位生长法，原位生长法可实现对导电载体的直接改性。此外，还报道了表征LDHs结构和形态最广泛使用的技术，因为它们的电化学性能与这些特征密切相关。最后，讨论了LDHs作为纳米材料合成时在传感、析氧反应及其他能源问题等方面的一些电催化应用。
