Temperature-Responsive Polyoxometalates-Based Materials: From Underlying Mechanism to Promising Applications

Abstract

Polyoxometalates (POMs) are multifunctional anionic metal-oxygen complexes with structural and electronic diversity, as well as tunable acid-base and redox properties, resulting in their potential as building blocks for constructing temperature-responsive polyoxometalates-based materials (TRPMs). TRPMs represent a class of intelligent materials exhibiting property changes in response to temperature fluctuations, offering distinctive applications in various fields such as catalysis, medicine, sensors, imaging, and so on. Though many TRPMs are reported, a systematic review including recent advances is still absent. This review provides insights into recent advancements in temperature-responsive mechanisms, nanostructure design strategies, and the characterization of TRPMs. Special emphasis is placed on enhancing the temperature-responsive properties of TRPMs by incorporating POMs into suitable organic ligands, such as ionic liquid cations, deep eutectic solvent cations, cationic surfactants, and polymers. The incorporation of organic ligands with POMs not only enables temperature-responsive phase transitions but also enhances other properties, such as catalyst selectivity and drug loading capacity, expanding TRPMs applications. Consequently, this review summarizes the applications of TRPMs in catalysis, drug delivery and release, and chemical sensing, as well as discusses future technological challenges. The in-depth understanding of TRPMs may help in the design of TRPMs from the nanoscale, guiding and inspiring future development.