Layered double hydroxides (LDHs) are an emergent class of biocompatible inorganic lamellar nanomaterials that have attracted significant research interest owing to their high surface-to-volume ratio, the capability to accumulate specific molecules, and the timely release to targets. Their unique properties have been employed for applications in organic catalysis, photocatalysis, sensors, drug delivery, and cell biology. Given the widespread contemporary interest in these topics, time-to-time it urges to review the recent progresses. This review aims to summarize the most recent cutting-edge reports appearing in the last years. It firstly focuses on the application of LDHs as catalysts in relevant chemical reactions and as photocatalysts for organic molecule degradation, water splitting reaction, CO₂ conversion, and reduction. Subsequently, the emerging role of these materials in biological applications is discussed, specifically focusing on their use as biosensors, DNA, RNA, and drug delivery, finally elucidating their suitability as contrast agents and for cellular differentiation. Concluding remarks and future prospects deal with future applications of LDHs, encouraging researches in better understanding the fundamental mechanisms involved in catalytic and photocatalytic processes, and the molecular pathways that are activated by the interaction of LDHs with cells in terms of both uptake mechanisms and nanotoxicology effects.

Over the past decade, halide perovskite systems have captured widespread attention among researchers since their exceptional photovoltaic (PV) performance is disclosed. The unique combination of optoelectronic properties and solution processability shown by these materials has enabled perovskite solar cells (PSCs) to reach efficiencies higher than 25% at low fabrication costs. Moreover, PSCs display enormous potential for modern unconventional PV applications, since they can be made lightweight, semitransparent (ST), and/or flexible by means of appropriate design strategies. In particular, by enabling transparency and high efficiency simultaneously, ST‐PSCs hold great promise for future versatile utilization in the context of building‐integrated PVs (BIPVs) or as top cells to be coupled with conventional lower‐bandgap bottom cells in tandem PV devices. The present review aims to provide a detailed overview of latest research about ST‐PSCs for BIPVs and tandems, by critically reporting on the most updated and effective design strategies in view of these two possible future applications. The differences and similarities between the available approaches are punctually highlighted, emphasizing the importance of a rigorous application‐orientated ST‐PSC design. Finally, the main challenges and issues about device design, operation, and stability that need to be addressed before commercialization are thoroughly scanned.